Method and user equipment for hybrid automatic repeat request process identity selection

ABSTRACT

A method and a user equipment for HARQ process ID selection are provided. The method includes: receiving a configuration message to configure a Configured Grant (CG) configuration and a set of HARQ process IDs that is available for the CG configuration, the set of HARQ process IDs including a first HARQ process ID for retransmission and a second HARQ process ID for initial transmission; determining that a CG physical uplink shared channel (PUSCH) corresponding to the CG configuration becomes available for transmission; selecting, based on a first HARQ process ID selection procedure, the first HARQ process ID or the second HARQ process ID from the set of HARQ process IDs for the CG PUSCH; and transmitting, based on the selected first or second HARQ process ID, a first Medium Access Control (MAC) Protocol Data Unit (PDU) for retransmission or a second MAC PDU for initial transmission on the CG PUSCH.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present disclosure claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 63/173,240, filed on Apr. 9,2021, entitled “METHOD AND APPARATUS TO SUPPORT URLLC IN UNLICENSED ANDCONTROLLED ENVIRONMENT,” the content of which is hereby fullyincorporated by reference into the present disclosure for all purposes.

FIELD

The present disclosure is related to wireless communication and, moreparticularly, to a method and a user equipment (UE) for hybrid automaticrepeat request (HARQ) identity (ID) selection in next generationwireless communication networks.

BACKGROUND

Various efforts have been made to improve different aspects of wirelesscommunication for cellular wireless communication systems, such as 5GNew Radio (NR), by improving data rate, latency, reliability, andmobility. The 5G NR system is designed to provide flexibility andconfigurability to optimize network services and types, accommodatingvarious use cases such as enhanced Mobile Broadband (eMBB), massiveMachine-Type Communication (mMTC), and Ultra-Reliable and Low-LatencyCommunication (URLLC). However, as the demand for radio access continuesto increase, there exists a need for further improvements in the art.

SUMMARY

The present disclosure is related to a method and a user equipment forhybrid automatic repeat request (HARQ) identity (ID) selection in nextgeneration wireless communication networks.

In a first aspect of the present disclosure, a method performed by auser equipment (UE) for HARQ ID selection is provided. The methodincludes: receiving a configuration message to configure a ConfiguredGrant (CG) configuration and a set of HARQ process IDs that is availablefor the CG configuration, the set of HARQ process IDs including a firstHARQ process ID for retransmission and a second HARQ process ID forinitial transmission; determining that a CG physical uplink sharedchannel (PUSCH) corresponding to the CG configuration becomes availablefor transmission; selecting, based on a first HARQ process ID selectionprocedure, the first HARQ process ID or the second HARQ process ID fromthe set of HARQ process IDs for the CG PUSCH; and transmitting, based onthe selected first or second HARQ process ID, a first Medium AccessControl (MAC) Protocol Data Unit (PDU) for the retransmission or asecond MAC PDU for the initial transmission on the CG PUSCH. The firstHARQ process ID selection procedure includes: determining a priority offirst data multiplexed in the first MAC PDU as a first priority of thefirst HARQ process ID; determining a priority of second data to bemultiplexed in the second MAC PDU as a second priority of the secondHARQ process ID; selecting, based on the first priority and the secondpriority, the first HARQ process ID or the second HARQ process ID fromthe set of HARQ process IDs for the CG PUSCH; and prioritizing the firstHARQ process ID over the second HARQ process ID in a case that the firstpriority is equal to the second priority.

In an implementation of the first aspect of the present disclosure, thefirst data is from a first set of Logical Channels (LCHs), the seconddata is from a second set of LCHs, the priority of the first data isdetermined based on an LCH with a highest LCH priority among the firstset of LCHs, and the priority of the second data is determined based onan LCH with a highest LCH priority among the second set of LCHs.

In an implementation of the first aspect of the present disclosure, thefirst HARQ process ID selection procedure further includes: selectingthe first HARQ process ID for the CG PUSCH in a case that the firstpriority is higher than the second priority; and selecting the secondHARQ process ID for the CG PUSCH in a case that the second priority ishigher than the first priority.

In an implementation of the first aspect of the present disclosure, themethod further includes: selecting, based on the first HARQ process IDselection procedure, the first HARQ process ID or the second HARQprocess ID from the set of HARQ process IDs for the CG PUSCH in a casethat a Logical Channel (LCH)-based prioritization indication, a CGretransmission timer, and an Information Element (IE) for enabling thefirst HARQ process ID selection procedure are configured.

In an implementation of the first aspect of the present disclosure, theIE is configured for the CG configuration or for a MAC entity of the UE.

In an implementation of the first aspect of the present disclosure, themethod further includes: selecting, based on a second HARQ process IDselection procedure, the first HARQ process ID or the second HARQprocess ID from the set of HARQ process IDs for the CG PUSCH in a casethat at least one of the LCH-based prioritization indication, the CGretransmission timer, and the IE is not configured. The second HARQprocess ID selection procedure includes: prioritizing the first HARQprocess ID over the second HARQ process ID.

In an implementation of the first aspect of the present disclosure,prioritizing the first HARQ process ID over the second HARQ process IDcomprises: selecting the first HARQ process ID for the CG PUSCH.

In a second aspect of the present disclosure, a UE for HARQ ID selectionis provided. The UE includes one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon; and at least one processor coupled to the one or morenon-transitory computer-readable media. The at least one processor isconfigured to execute the computer-executable instructions to: receive aconfiguration message to configure a Configured Grant (CG) configurationand a set of HARQ process IDs that is available for the CGconfiguration, the set of HARQ process IDs including a first HARQprocess ID for retransmission and a second HARQ process ID for initialtransmission; determining that a CG physical uplink shared channel(PUSCH) corresponding to the CG configuration becomes available fortransmission; select, based on a first HARQ process ID selectionprocedure, the first HARQ process ID or the second HARQ process ID fromthe set of HARQ process IDs for the CG PUSCH; and transmit, based on theselected first or second HARQ process ID, a first Medium Access Control(MAC) Protocol Data Unit (PDU) for the retransmission or a second MACPDU for the initial transmission on the CG PUSCH, wherein the first HARQprocess ID selection procedure includes: determining a priority of firstdata multiplexed in the first MAC PDU as a first priority of the firstHARQ process ID; determining a priority of second data to be multiplexedin the second MAC PDU as a second priority of the second HARQ processID; selecting, based on the first priority and the second priority, thefirst HARQ process ID or the second HARQ process ID from the set of HARQprocess IDs for the CG PUSCH; and prioritizing the first HARQ process IDover the second HARQ process ID in a case that the first priority isequal to the second priority.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the disclosure are best understood from the followingdetailed disclosure when read with the accompanying drawings. Variousfeatures are not drawn to scale. Dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic diagram illustrating a configured grant (CG) timeroperation in new radio (NR), according to an example implementation ofthe present disclosure.

FIG. 2 is a schematic diagram illustrating an operation of the CG timer,according to an example implementation of the present disclosure.

FIG. 3 is a schematic diagram illustrating an issue associated with theautonomous transmission of a deprioritized MAC PDU, according to anexample implementation of the present disclosure.

FIG. 4 is a flowchart illustrating a method for selecting HARQ processID of a CG PUSCH, according to an example implementation of the presentdisclosure.

FIG. 5 is a schematic diagram illustrating another issue associated withthe autonomous transmission of a deprioritized MAC PDU, according to anexample implementation of the present disclosure.

FIG. 6 is a schematic diagram illustrating new conditions to stop the CGtimer, according to an example implementation of the present disclosure.

FIG. 7 is a flowchart illustrating a method for a UE for HARQ IDselection, according to an example implementation of the presentdisclosure

FIG. 8 is a block diagram illustrating a node for wirelesscommunication, according to an example implementation of the presentdisclosure.

DESCRIPTION

The acronyms in the present application are defined as follows, unlessotherwise specified:

Acronym Full name 3GPP 3^(rd) Generation Partnership Project 5G 5^(th)generation 5GC 5G Core ACK Acknowledgement ASIC Application SpecificIntegrated Circuitry ATG Air-To-Ground BDS Beidou Navigation SatelliteSystem BLER Block Error Rate BS Base Station BSC BS Controller BSDBuffer Size Duration BWP Bandwidth Part CA Carrier Aggregation CBRAContention-Based Random Access CC Component Carrier CCA Clear ChannelAssessment CCCH Common Control Channel CD-ROM Compact Disc Read-OnlyMemory CE Control Element CFRA Contention Free Random Access CGConfigured Grant CG Cell Group CN Core Network COT Channel OccupancyTime CP Cyclic Prefix CRC Cyclic Redundancy Check GRID ContentionResolution Identity C-RNTI Cell-Radio Network Temporary IdentifierCI-RNTI Cancellation Indication-RNTI CS-RNTI Configured Scheduling-RNTICSI Channel State Information dB Decibel DC Dual Connectivity DCIDownlink Control Information DFI Downlink Feedback Information DLDownlink DL-SCH Downlink-Shared Channel DMRS Demodulation ReferenceSignal DRX Discontinuous Reception DSP Digital Signal Processor e-LTEevolved LTE E-UTRA Evolved Universal Terrestrial Radio Access E-UTRANEvolved Universal Terrestrial Radio Access Network EDGE Enhanced Datarates for GSM Evolution EEPROM Electrically Erasable ProgrammableRead-Only Memory eMBB enhanced Mobile Broadband eMTC massiveMachine-Type Communication EPC Evolved Packet Core EPROM ErasableProgrammable Read-Only Memory FBE Frame based equipment FFP Fixed FramePeriod GC-PDCCH Group Common Physical Downlink Control Channel GEOGeostationary Earth Orbit GERAN EDGE RAN GLONASS Global NavigationSatellite System gNB Next Generation Node B GNSS Global NavigationSatellite System GPRS General Packet Radio Service GPS GlobalPositioning System GSM Global System for Mobile communication HAPS HighAltitude Platform Station HARQ Hybrid Automatic Repeat request HSPAHigh-Speed Packet Access ID Identifier IE Information Element IIoTIndustrial Internet of Things LAA Licensed Assisted Access LBT ListenBefore Talk LCH Logical Channel LCID Logical Channel Identity LCPLogical Channel Prioritization LDPC Low-Density Parity-Check LEO LowEarth Orbit LSB Least Significant Bit LTE Long-Term Evolution LTE-ALTE-Advanced L1 Layer 1 MAC Medium Access Control MCG Master Cell GroupMCS-C-RNTI Modulation Coding Scheme Cell Radio Network TemporaryIdentifier MEO Medium Earth Orbit MIMO Multi-input Multi-output MSB MostSignificant Bit Msg Message NACK Negative Acknowledgment NAS Non-AccessStratum NDI New Data Indicator NGEO Non-Geostationary Earth Orbit NGSONon-Geosynchronous Orbit NR New RAT/Radio NR-U New Radio Unlicensed NTNNon-Terrestrial Network NW Network OFDM Orthogonal Frequency-DivisionMultiplexing PBCH Physical Broadcast Channel PBR Prioritized Bit RatePCell Primacy Cell PDCCH Physical Downlink Control Channel PDCP PacketData Convergence Protocol PDSCH Physical Downlink Shared Channel PDUProtocol Data Unit PHY Physical PRACH Physical Random Access Channel PRBPhysical Resource Block PRU PUSCH Resource Unit ProSe Proximity ServicePSCell Primary Secondary Cell PUCCH Physical Uplink Control ChannelPUSCH Physical Uplink Shared Channel PO PUSCH Occasion QoS Quality ofService RA Random Access RACH Random Access Channel RAM Random AccessMemory RAN Radio Access Network RAR Random Access Response RAT RadioAccess Technology Rel Release RLAN Radio Local Area Network REC RadioLink Control RMSI Remaining Minimum System Information RNC Radio NetworkController RNTI Radio Network Temporary Identifier RO PRACH Occasion ROMRead Only Memory RRC Radio Resource Control RSRP Reference SignalReceived Power RTT Round Trip Time RV Redundancy Version SCell SecondaryCell SCG Secondary Cell Group SCS Subcarrier Spacing SDAP Service DataAdaptation Protocol SDU Service Data Unit SFN System Frame Number SISystem Information SL Sidelink SL-SCH Sidelink-Shared Channel SNSequence Number SpCell Special Cell SPS Semi-Persistent Scheduling SRScheduling Request SRS Sounding Reference Signal SS Search Space SSBSynchronization Signal Block SUL Supplementary Uplink TA Timing AdvanceTAG Timing Advance Group TB Transport Block TBS Transport Block SizeTC-RNTI Temporary C-RNTI TPC Transmit Power Control TR Technical ReportTS Technical Specification TX Transmission TRP Transmission andReception Point UCE Unlicensed Controlled Environment UCI Uplink ControlInformation UE User Equipment UL Uplink UL-SCH Uplink-Shared ChannelUMTS Universal Mobile Telecommunications System URLLC Ultra-Reliable andLow-Latency Communication V2X Vehicle to Everything W-CDMA Wideband-CodeDivision Multiple Access WG Working Group WI Working Item WiMAXWorldwide Interoperability for Microwave Access

The following contains specific information related to implementationsof the present disclosure. The drawings and their accompanying detaileddisclosure are merely directed to implementations. However, the presentdisclosure is not limited to these implementations. Other variations andimplementations of the present disclosure will be obvious to thoseskilled in the art. Unless noted otherwise, like or correspondingelements among the drawings may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale and are not intended tocorrespond to actual relative dimensions.

For the purposes of consistency and ease of understanding, like featuresmay be identified (although, in some examples, not illustrated) by thesame numerals in the drawings. However, the features in differentimplementations may be different in other respects and shall not benarrowly confined to what is illustrated in the drawings.

The phrases “in one implementation,” or “in some implementations,” mayeach refer to one or more of the same or different implementations. Theterm “coupled” is defined as connected whether directly or indirectlyvia intervening components and is not necessarily limited to physicalconnections. The term “comprising” means “including, but not necessarilylimited to” and specifically indicates open-ended inclusion ormembership in the so-disclosed combination, group, series or equivalent.The expression “at least one of A, B and C” or “at least one of thefollowing: A, B and C” means “only A, or only B, or only C, or anycombination of A, B and C.”

For the purposes of explanation and non-limitation, specific detailssuch as functional entities, techniques, protocols, and standards areset forth for providing an understanding of the disclosed technology. Inother examples, detailed disclosure of well-known methods, technologies,systems, and architectures are omitted so as not to obscure the presentdisclosure with unnecessary details.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) disclosed may be implemented by hardware,software or a combination of software and hardware. Disclosed functionsmay correspond to modules which may be software, hardware, firmware, orany combination thereof. A software implementation may include computerexecutable instructions stored on a computer readable medium such asmemory or other type of storage devices. One or more microprocessors orgeneral-purpose computers with communication processing capability maybe programmed with corresponding executable instructions and perform thedisclosed network function(s) or algorithm(s). The microprocessors orgeneral-purpose computers may include Application-Specific IntegratedCircuits (ASICs), programmable logic arrays, and/or using one or moreDigital Signal Processor (DSPs). Although some of the disclosedimplementations are oriented to software installed and executing oncomputer hardware, alternative implementations implemented as firmwareor as hardware or as a combination of hardware and software are wellwithin the scope of the present disclosure.

The computer-readable medium includes but is not limited to RandomAccess Memory (RAM), Read Only Memory (ROM), Erasable ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture, such as a Long-TermEvolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-AdvancedPro system, or a 5G NR Radio Access Network (RAN), typically includes atleast one base station (BS), at least one UE, and one or more optionalnetwork elements that provide connection within a network. The UEcommunicates with the network, such as a Core Network (CN), an EvolvedPacket Core (EPC) network, an Evolved Universal Terrestrial RAN(E-UTRAN), a 5G Core (5GC), or an internet via a RAN established by oneor more BSs.

A UE may include but is not limited to a mobile station, a mobileterminal or device, or a user communication radio terminal. The UE maybe a portable radio equipment that includes but is not limited to amobile phone, a tablet, a wearable device, a sensor, a vehicle, or aPersonal Digital Assistant (PDA) with wireless communication capability.The UE is configured to receive and transmit signals over an airinterface to one or more cells in a RAN.

ABS may be configured to provide communication services according to atleast a Radio Access Technology (RAT) such as Worldwide Interoperabilityfor Microwave Access (WiMAX), Global System for Mobile communications(GSM) that is often referred to as 2G, GSM Enhanced Data rates for GSMEvolution (EDGE) RAN (GERAN), General Packet Radio Service (GPRS),Universal Mobile Telecommunication System (UMTS) that is often referredto as 3G based on basic wideband-code division multiple access (W-CDMA),high-speed packet access (HSPA), LTE, LTE-A, evolved LTE (eLTE) that isLTE connected to 5GC, NR (often referred to as 5G), and/or LTE-A Pro.However, the scope of the present disclosure is not limited to theseprotocols.

The BS may include but is not limited to a node B (NB) in the UMTS, anevolved node B (eNB) in LTE or LTE-A, a radio network controller (RNC)in UMTS, a BS controller (BSC) in the GSM/GERAN, an ng-eNB in an EvolvedUniversal Terrestrial Radio Access (E-UTRA) BS in connection with 5GC, anext generation Node B (gNB) in the 5G-RAN, or any other apparatuscapable of controlling radio communication and managing radio resourceswithin a cell. The BS may serve one or more UEs via a radio interface.

The BS is operable to provide radio coverage to a specific geographicalarea using a plurality of cells forming the RAN. The BS supports theoperations of the cells. Each cell is operable to provide services to atleast one UE within its radio coverage. Each cell (often referred to asa serving cell) may provide services to one or more UEs within its radiocoverage such that each cell schedules the DL and optionally ULresources to at least one UE within its radio coverage for DL andoptionally UL packet transmissions. The BS can communicate with one ormore UEs in the radio communication system via the plurality of cells. Acell may allocate sidelink (SL) resources for supporting ProximityService (ProSe) or Vehicle to Everything (V2X) service. Each cell mayhave overlapped coverage areas with other cells.

As discussed above, the frame structure for NR supports flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements such as Enhanced Mobile Broadband (eMBB),Massive Machine Type Communication (mMTC), and Ultra-Reliable andLow-Latency Communication (URLLC), while fulfilling high reliability,high data rate, and low latency requirements. The OrthogonalFrequency-Division Multiplexing (OFDM) technology in the 3rd GenerationPartnership Project (3GPP) may serve as a baseline for an NR waveform.The scalable OFDM numerology such as adaptive sub-carrier spacing,channel bandwidth, and Cyclic Prefix (CP) may also be used.Additionally, two coding schemes are considered for NR, specificallyLow-Density Parity-Check (LDPC) code and Polar Code. The coding schemeadaption may be configured based on channel conditions and/or serviceapplications.

Moreover, it is also considered that in a transmission time interval TXof a single NR frame, downlink (DL) transmission data, a guard period,and uplink (UL) transmission data should at least be included, where therespective portions of the DL transmission data, the guard period, andthe UL transmission data should also be configurable, for example, basedon the network dynamics of NR. In addition, sidelink resources may alsobe provided in an NR frame to support ProSe services.

In addition, the terms “system” and “network” herein may be usedinterchangeably. The term “and/or” herein is only an associationrelationship for describing associated objects and represents that theserelationships may exist. For example, A and/or B may indicate that: Aexists alone, A and B exist at the same time, or B exists alone. Inaddition, the character “/” herein generally represents that the formerand latter associated objects are in an “or” relationship.

Examples of some selected terms are provided as follows.

A network may be a fixed station or base station used for communicatingwith the terminals and may also be referred to as an access point, aNode B, a base station, an enhanced base station, an eNodeB, a gNodeB(gNB), or some other terminology.

An unlicensed environment may be referred to as a shared spectrum, anunlicensed spectrum, and/or an unlicensed band, a cell that operateswith shared spectrum channel access, etc.

A CG may include a PCell, a PSCell, and/or a SCell.

An SpCell may include a PCell and a PSCell.

A UL resource may include a RACH resource, a PUCCH resource, and/or aPUSCH resource. The UL resource may be scheduled by dynamic grant (e.g.,via PDCCH) and/or configured by RRC (e.g., type 1/type 2 configured ULgrant or pre-configured in an RRC configuration).

The MAC entity may be referred to as the UE.

Intra-UE prioritization may be needed if two or more UL resources(scheduled/configured in the same serving cell) overlap in the timedomain, in which a UE selects one of the overlapping UL resources fortransmission.

The overlap of the resources may mean the resources partially overlapand/or fully overlap.

The configured grant configuration may include (but is not limited to) aconfigured grant Type 1 or a configured grant Type 2.

There are two types of transmission without dynamic grant:

(a) Configured grant Type 1, where an uplink grant is provided by an RRCmessage and stored as a configured uplink grant.

(b) Configured grant Type 2, where an uplink grant is provided by aPDCCH and stored or cleared as a configured uplink grant based on L1signaling indicating configured uplink grant activation or deactivation.

A configured uplink grant may be referred to as a PUSCH resource thatcorresponds to a configured grant configuration.

A CG PUSCH may be referred to as a PUSCH that corresponds to aconfigured grant configuration.

A HARQ-ACK may be either an ACK or a NACK.

The UE may consider a generated MAC PDU/TB as being obtained.

Frame Based Equipment (FBE) may implement a Listen Before Talk(LBT)-based Channel Access Mechanism to detect the presence of otherRadio Local Area Network (RLAN) transmissions on an operating channel.

In some implementations of the present disclosure, intra-UEprioritization may be needed by a UE if two or more UL resources(scheduled/configured in the same serving cell) overlap in the timedomain. As a result of the intra-UE prioritization, the UE may selectone of the overlapping UL resources for transmission. The selected ULresource may be referred to as the prioritized UL resource, and the MACPDU/TB to be transmitted on the UL resource may be referred to as theprioritized MAC PDU/TB. In contrast, the UL resource(s) that are notselected may be referred to as the deprioritized UL resource(s), and theMAC PDU(s)/TB(s) to be transmitted on the deprioritized UL resource(s)may be referred to as the deprioritized MAC PDU(s)/TB(s).

Either the network may indicate to a UE, or the UE may determine itself,whether to use a Type 1 channel access procedure or a Type 2 channelaccess procedure before performing a UL transmission. Specifically, aType 2 channel access procedure may be further classified into a Type2A, Type 2B, Type 2C, or Type 2D channel access procedure, as specifiedin 3GPP TS 37.213.

A channel occupancy initiated by an initiating device (e.g., gNB) andshared with a responding device (e.g., UE) may satisfy the followingconditions (a)-(e).

(a) The initiating device (e.g., gNB) may transmit a DL (or UL)transmission burst(s) starting at the beginning of the COT immediatelyafter performing channel access and sensing the channel to be idle forat least a sensing slot duration T_sl=9 μs. If the channel is sensed tobe busy (after performing channel access), the initiating device (e.g.,gNB) may not perform any transmission during the current COT.

(b) The initiating device (e.g., gNB) may transmit a DL (or UL)transmission burst(s) within the COT immediately after performingchannel access and sensing the channel to be idle for at least a sensingslot duration T_sl=9 μs if the gap between the DL (or UL) transmissionburst(s) and any previous transmission burst is more than 16 μs.

(c) The initiating device (e.g., gNB) may transmit DL (or UL)transmission burst(s) after UL (or DL) transmission burst(s) within theCOT without performing channel access/sensing the channel if the gapbetween the DL (or UL) and UL (or DL) transmission bursts is at most 16μs.

(d) A responding device (e.g., UE) may transmit UL (or DL) transmissionburst(s) after detection of a DL (or UL) transmission burst(s) withinthe COT (acquired by the initiating device) as follows. If the gapbetween the UL (or DL) and DL (or UL) transmission bursts is at most 16μs, the responding device (e.g., UE) may transmit UL (or DL)transmission burst(s) after a DL (or UL) transmission burst(s) withinthe COT (acquired by the initiating device) without performing channelaccess/sensing the channel. If the gap between the UL (or DL) and DL (orUL) transmission bursts is more than 16 μs, the responding device (e.g.,UE) may transmit UL (or DL) transmission burst(s) after a DL (or UL)transmission burst(s) within the COT (acquired by the initiating device)after performing channel access and sensing the channel to be idle forat least a sensing slot duration T_sl=9 μs within a 25 μs intervalending immediately before transmission.

(e) The initiating device (e.g., gNB) and responding devices (e.g., UEs)may not transmit any transmissions in a set of consecutive symbols for aduration of at least T_z=max (0.05T_x, 100 μs) before the start of thenext COT.

If a UE fails to access the channel(s) (e.g., LBT failure) prior to anintended UL transmission to a network, Layer 1 (e.g., PHY) notifieshigher layers (e.g., MAC) about the channel access failure (e.g., bysending an LBT failure indication).

When the timer cg-RetransmissionTimer is configured and the HARQ entityobtains a MAC PDU to transmit, the corresponding HARQ process isconsidered to be pending. For a configured uplink grant configured withcg-RetransmissionTimer, each associated HARQ process is considered asnot pending when any of the following conditions (a)-(c) is satisfied.

(a) A transmission is performed on the HARQ process and an LBT failureindication is not received from lower layers.

(b) The configured uplink grant is initialized and the HARQ process isnot associated with another active configured uplink grant.

(c) A HARQ buffer for the HARQ process is flushed.

A HARQ process ID (of a configured grant configuration) may beconsidered for retransmission if either of the following conditions (a)and (b) is satisfied.

(a) The timer configuredGrantTimer of the HARQ process ID is running(and the HARQ process is pending/not pending).

(b) The configuredGrantTimer for the HARQ process ID is not running andthe HARQ process is pending.

A HARQ process (of a configured grant configuration) may be consideredfor new transmission (e.g., initial transmission) if theconfiguredGrantTimer of the HARQ process ID is not running (and the HARQPROCESS ID is not pending).

A UL resource may also be referred to as a UL grant.

If lch-BasedPrioritization is configured at a UE, LCH-basedprioritization may be performed by the UE when two or more UL resources(e.g., one or more PUSCH resources and/or one or more PUCCH resourcesfor SR transmission) overlap in the time-domain (in the same servingcell). As a result of LCH-based prioritization, the UE may determine oneprioritized UL resource out of the time-domain overlapping UL resourcesfor transmission. Moreover, the UE may determine the UL resource(s) thatoverlaps the prioritized UL resource as a deprioritized UL resource(s).

If autonomousTx is configured in a CG configuration, in the case that adeprioritized UL resource is a CG PUSCH from the CG configuration,namely CG PUSCH-deprioritized, a generated MAC PDU for the HARQ processof CG PUSCH-deprioritized may be autonomously transmitted on the nextavailable CG PUSCH for new transmission, namely CG PUSCH-autonomousTx.In some implementations, CG PUSCH-deprioritized and CGPUSCH-autonomousTx may have the same HARQ process ID, CG configuration,and TBS as the deprioritized CG PUSCH. Note that autonomousTx may needto be configured in the same CG configuration as the CGPUSCH-deprioritized (and CG PUSCH-autonomousTx) to enable autonomoustransmission of the deprioritized MAC PDU.

If cg-RetransmissionTimer is configured in a CG configuration and the UEhas a pending HARQ process ID due to LBT failure (e.g., detection of anLBT failure indication) before transmission on a CG PUSCH, namely CGPUSCH-LBT Failure, a generated MAC PDU for the HARQ process of CGPUSCH-LBT Failure may be retransmitted on a CG PUSCH for retransmission,namely CG PUSCH-retransmission, when cg-RetransmissionTimer for the HARQprocess of CG PUSCH-LBT is not running. In some implementations, CGPUSCH-LBT Failure and CG PUSCH-retransmission may have the same HARQprocess ID and TBS as the deprioritized CG PUSCH. In someimplementations, cg-RetransmissionTimer may be configured in the CGconfiguration that CG PUSCH-LBT Failure and/or CG PUSCH-retransmissioncorrespond to.

The HARQ process ID for new transmission may have least one of thefollowing characteristics (a)-(e).

(a) The HARQ process ID for new transmission does not correspond to apending MAC PDU.

(b) The HARQ process ID for new transmission may not be identified aspending.

(c) The configuredGrantTimer of the HARQ process ID for new transmissionmay not be configured, or may be configured and is not running.

(d) The cg-RetransmissionTimer of the HARQ process ID for newtransmission may not be configured, or may be configured and is notrunning.

(e) The HARQ process ID of new transmission may not correspond to adeprioritized CG PUSCH/MAC PDU.

The HARQ process ID for retransmission may have least one of thefollowing characteristics (a)-(e).

(a) The HARQ process ID for retransmission may include a pending MACPDU.

(b) The HARQ process ID for retransmission may be identified as pending.

(c) The configuredGrantTimer of the HARQ process ID for retransmissionmay not be configured, or may be configured and is running.

(d) The cg-RetransmissionTimer of the HARQ process ID for retransmissionmay not be configured, or may be configured and is not running.

(e) DFI indicating ACK may not have been received for the HARQ processID for retransmission.

The LCH-based prioritization is described as follows.

For the MAC entity configured with lch-basedPrioritization, priority ofan uplink grant is determined by the highest priority among prioritiesof the logical channels that are multiplexed (i.e. the MAC PDU totransmit is already stored in the HARQ buffer) or have data availablethat may be multiplexed (i.e. the MAC PDU to transmit is not stored inthe HARQ buffer) in the MAC PDU, according to the mapping restrictionsas described in clause 5.4.3.1.2 of 3GPP TS 38.321. The priority of anuplink grant for which no data for logical channels is multiplexed ormay be multiplexed in the MAC PDU is lower than either the priority ofan uplink grant for which data for any logical channels is multiplexedor may be multiplexed in the MAC PDU or the priority of the logicalchannel triggering an SR.

For the MAC entity configured with lch-basedPrioritization, if thecorresponding PUSCH transmission of a configured uplink grant iscancelled by CI-RNTI as specified in clause 11.2A of 3GPP TS 38.213, orcancelled by a high PHY-priority PUCCH transmission as specified inclause 9 of 3GPP TS 38.213, this configured uplink grant is consideredto be a de-prioritized uplink grant. If this deprioritized uplink grantis configured with autonomousTx, the configuredGrantTimer for thecorresponding HARQ process of this de-prioritized uplink grant may bestopped if it is running.

Table 1 below shows an example of MAC entity behavior when the MACentity is configured with lch-basedPrioritization for each uplink grantwhose associated PUSCH may be transmitted by lower layers.

TABLE 1 When the MAC entity is configured with lch-basedPrioritization,for each uplink grant whose associated PUSCH may be transmitted by lowerlayers, the MAC entity may: 1>  if the uplink grant is addressed toCS-RNTI with NDI = 1 or C-RNTI:  2> if there is no overlapping PUSCHduration of a configured uplink grant which was not already de-prioritized, in the same BWP whose priority is higher than the priorityof the uplink grant; and  2> if there is no overlapping PUCCH resourcewith an SR transmission which was not already de- prioritized and thepriority of the logical channel that triggered the SR is higher than thepriority of the uplink grant: 3>  consider the uplink grant as aprioritized uplink grant; 3>  consider the other overlapping uplinkgrant(s), if any, as a de-prioritized uplink grant(s); 3>  consider theother overlapping SR transmission(s), if any, as a de-prioritized SRtransmission(s). 1>  else if the uplink grant is a configured uplinkgrant:  2> if there is no overlapping PUSCH duration of anotherconfigured uplink grant which was not already de-prioritized, in thesame BWP, whose priority is higher than the priority of the uplinkgrant; and  2> if there is no overlapping PUSCH duration of an uplinkgrant addressed to CS-RNTI with NDI = 1 or C-RNTI which was not alreadyde-prioritized, in the same BWP, whose priority is higher than or equalto the priority of the uplink grant; and  2> if there is no overlappingPUCCH resource with an SR transmission which was not already de-prioritized and the priority of the logical channel that triggered theSR is higher than the priority of the uplink grant: 3>  consider theuplink grant as a prioritized uplink grant; 3>  consider the otheroverlapping uplink grant(s), if any, as a de-prioritized uplinkgrant(s); 3>  if the de-prioritized uplink grant(s) is a configureduplink grant configured with autonomousTx  whose PUSCH has alreadystarted:   4> stop the configuredGrantTimer for the corresponding HARQprocess of the de-prioritized    uplink grant(s). 3>  consider the otheroverlapping SR transmission(s), if any, as a de-prioritized SRtransmission(s).

If the MAC entity is configured with lch-basedPrioritization and ifthere is an overlapping PUSCH duration of at least two configured uplinkgrants whose priorities are equal, the prioritized uplink grant isdetermined by a UE-specific implementation. If the MAC entity is notconfigured with lch-basedPrioritzation and if there is an overlappingPUSCH duration of at least two configured uplink grants, it is up to theUE-specific implementation to choose one of the configured uplinkgrants.

Table 2 below shows an example of MAC entity behavior.

TABLE 2 For each Serving Cell and each configured uplink grant, ifconfigured and activated, the MAC entity may: 1>  if the MAC entity isconfigured with lch-basedPrioritization, and the PUSCH duration of the configured uplink grant does not overlap with the PUSCH duration of anuplink grant received in  a Random Access Response or with the PUSCHduration of an uplink grant addressed to  Temporary C-RNTI or the PUSCHduration of a MSGA payload for this Serving Cell; or 1>  if the MACentity is not configured with lch-basedPrioritization, and the PUSCHduration of the  configured uplink grant does not overlap with the PUSCHduration of an uplink grant received  on the PDCCH or in a Random AccessResponse or the PUSCH duration of a MSGA payload for  this Serving Cell: 2> set the HARQ process ID to the HARQ process ID associated with thisPUSCH duration;  2> if, for the corresponding HARQ process, theconfiguredGrantTimer is not running and cg- RetransmissionTimer is notconfigured (i.e. new transmission): 3>  consider the NDI bit for thecorresponding HARQ process to have been toggled; 3>  deliver theconfigured uplink grant and the associated HARQ information to the HARQentity.  2> else if the cg-RetransmissionTimer for the correspondingHARQ process is configured and not running, then for the correspondingHARQ process: 3>  if the configuredGrantTimer is not running, and theHARQ process is not pending (i.e. new  transmission):   4> consider theNDI bit to have been toggled;   4> deliver the configured uplink grantand the associated HARQ information to the HARQ entity. 3> else if theprevious uplink grant delivered to the HARQ entity for the same HARQprocess was a configured uplink grant (i.e. retransmission on configuredgrant):   4> deliver the configured uplink grant and the associated HARQinformation to the HARQ    entity.

Table 3 below shows an example of HARQ entity behavior.

TABLE 3 For each uplink grant, the HARQ entity may: 1>  identify theHARQ process associated with the grant, and for each identified HARQprocess: 2> if the received grant was not addressed to a TemporaryC-RNTI on a PDCCH, and the NDI provided in the associated HARQinformation has been toggled compared to the value in the previoustransmission of this TB of the HARQ process; or 2> if the uplink grantwas received on a PDCCH for the C-RNTI and the HARQ buffer of theidentified process is empty; or 2> if the uplink grant was received in aRandom Access Response (i.e. in a MAC RAR or a fallback RAR); or 2> ifthe uplink grant was determined as specified in clause 5.1.2a for thetransmission of the MSGA payload; or 2> if the uplink grant was receivedon PDCCH for the C-RNTI in ra-Response Window and the PDCCH successfullycompleted the Random Access procedure initiated for beam failurerecovery; or 2> if the uplink grant is part of a bundle of theconfigured uplink grant, and may be used for initial transmissionaccording to clause 6.1.2.3 of 3GPP TS 38.214, and if no MAC PDU hasbeen obtained for this bundle: 3>  if there is a MAC PDU in the MSGAbuffer and the uplink grant determined as specified in  clause 5.1.2afor the transmission of the MSGA payload was selected; or 3>  if thereis a MAC PDU in the MSGA buffer and the uplink grant was received in afallbackRAR  and the fallbackRAR successfully completed the RandomAccess procedure:   4> obtain the MAC PDU to transmit from the MSGAbuffer. 3>  else if there is a MAC PDU in the Msg3 buffer and the uplinkgrant was received in a  fallbackRAR:   4>obtain the MAC PDU to transmitfrom the Msg3 buffer. 3>  else if there is a MAC PDU in the Msg3 bufferand the uplink grant was received in a MAC  RAR; or: 3>  if there is aMAC PDU in the Msg3 buffer and the uplink grant was received on a PDCCHfor  the C-RNTI in ra-ResponseWindow and the PDCCH successfullycompleted the Random Access  procedure initiated for beam failurerecovery:   4> obtain the MAC PDU to transmit from the Msg3 buffer.   4>if the uplink grant size does not match the size of the obtained MACPDU; and   4> if the Random Access procedure was successfully completedupon receiving the uplink    grant:    5> indicate to the Multiplexingand assembly entity to include MAC subPDU(s) carrying     MAC SDU fromthe obtained MAC PDU in the subsequent uplink transmission;    5> obtainthe MAC PDU to transmit from the Multiplexing and assembly entity. 3> else if the uplink grant is a configured grant configured withautonomousTx; and 3>  if the previous configured uplink grant, in theBWP, for this HARQ process was not prioritized;  and 3>  if a MAC PDUhad already been obtained for this HARQ process; and 3>  if the uplinkgrant size matches the size of the obtained MAC PDU; and 3>  if none ofPUSCH transmission(s) of the obtained MAC PDU has been completelyperformed:   4> consider the MAC PDU has been obtained. 3>  else if theMAC entity is not configured with lch-basedPrioritization; or 3>  ifthis uplink grant is a prioritized uplink grant:   4> obtain the MAC PDUto transmit from the Multiplexing and assembly entity, if any; 3>  if aMAC PDU to transmit has been obtained:   4> if the uplink grant is not aconfigured grant configured with autonomousTx; or   4> if the uplinkgrant is a prioritized uplink grant:    5> deliver the MAC PDU and theuplink grant and the HARQ information of the TB to the     identifiedHARQ process;    5> instruct the identified HARQ process to trigger anew transmission;    5> if the uplink grant is a configured uplinkgrant:     6> start or restart the configuredGrantTimer, if configured,for the corresponding HARQ      process when the transmission isperformed if an LBT failure indication is not      received from lowerlayers;     6> start or restart the cg-RetransmissionTimer, ifconfigured, for the corresponding      HARQ process when thetransmission is performed if an LBT failure indication is      notreceived from lower layers.    5> if the uplink grant is addressed toC-RNTI, and the identified HARQ process is     configured for aconfigured uplink grant:     6> start or restart theconfiguredGrantTimer, if configured, for the corresponding HARQ     process when the transmission is performed if an LBT failureindication is not      received from lower layers.    5> ifcg-RetransmissionTimer is configured for the identified HARQ process;and    5> if the transmission is performed and an UBT failure indicationis received from lower     layers:     6> consider the identified HARQprocess as pending. 3>  else:   4> flush the HARQ buffer of theidentified HARQ process. 2> else (i.e. retransmission): 3>  if theuplink grant received on a PDCCH was addressed to CS-RNTI and if theHARQ buffer of  the identified process is empty; or 3>  if the uplinkgrant is part of a bundle and if no MAC PDU has been obtained for thisbundle; or 3>  if the uplink grant is part of a bundle of the configureduplink grant, and the PUSCH duration of  the uplink grant overlaps aPUSCH duration of another uplink grant received on the PDCCH or  anuplink grant received in a Random Access Response (i.e. MAC RAR orfallbackRAR) or an  uplink grant determined as specified in clause5.1.2a for MSGA payload for this Serving Cell; or: 3>  if the MAC entityis configured with lch-basedPrioritization and the uplink grant is not a prioritized uplink grant:   4> ignore the uplink grant. 3>  else:   4>deliver the uplink grant and the HARQ information (redundancy version)of the TB to the    identified HARQ process;   4> instruct theidentified HARQ process to trigger a retransmission;   4> if the uplinkgrant is addressed to CS-RNTI; or   4> if the uplink grant is addressedto C-RNTI, and the identified HARQ process is configured    for aconfigured uplink grant:    5> start or restart theconfiguredGrantTimer, if configured, for the corresponding HARQ    process when the transmission is performed if an LBT failureindication is not received     from lower layers.   4> if the uplinkgrant is a configured uplink grant:    5> if the identified HARQ processis pending:     6> start or restart the configuredGrantTimer, ifconfigured, for the corresponding HARQ      process when thetransmission is performed if an LBT failure indication is not     received from lower layers;    5> start or restart thecg-RetransmissionTimer, if configured, for the corresponding HARQ    process when the transmission is performed if an LBT failureindication is not received     from lower layers.   4> if the identifiedHARQ process is pending and the transmission is performed and an LBT   failure indication is not received from lower layers:    5> considerthe identified HARQ process as not pending.

When determining whether the NDI has been toggled compared to the valuein the previous transmission the MAC entity may ignore the NDI receivedin all uplink grants on a PDCCH for its Temporary C-RNTI. WhenconfiguredGrantTimer or cg-RetransmissionTimer is started or restartedby a PUSCH transmission, it may be started at the beginning of the firstsymbol of the PUSCH transmission.

NR-based Access to Unlicensed Spectrum has been agreed to by 3GPP as oneof the WIs for NR Rel-16. This WI specifies NR enhancements for a singleglobal solution framework for access to unlicensed spectrum whichenables operation of NR in the 5 GHz and the 6 GHz unlicensed bands,taking into account regional regulatory requirements. The NR-U designshould enable fair coexistence between already deployed Wi-Figenerations and NR-U, between NR-U and LTE-LAA, between different NR-Usystems, etc.

In an unlicensed spectrum, a UE may be required to perform channelaccess (e.g., LBT/CCA) before performing a transmission in order to makesure there is no other device occupying the channel where thetransmission is intended to be performed. For a channel access mechanismin NR-U, an LTE-LAA LBT mechanism may be adopted as baseline for the 5GHz band and adopted as the starting point of the design for the 6 GHzband. At least for band where absence of Wi-Fi may not be guaranteed(e.g., by regulation), LBT may be performed in units of 20 MHz. Ingeneral, there are 4 LBT categories. For NR-U, a UE may perform LBTusing one of the 4 LBT categories before performing a UL transmissionfor different transmissions in a COT (as defined below) and differentchannels/signals to be transmitted. Specifically, a UE may perform LBTusing different LBT categories before performing a UL transmission(e.g., PRACH, PUCCH, PUSCH, SRS transmission, etc.). LBT Categories 1-4are provided as follows.

Category 1: Immediate transmission after a short switching gap. This maybe used for a transmitter to immediately transmit after a switching gapinside a COT. More specifically, the switching gap from reception totransmission is to accommodate the transceiver turnaround time and is nolonger than 16 μs. Category 1 may also be known as a Type 2 UL channelaccess procedure.

Category 2: LBT without random back-off. The duration of time that thechannel (where transmission is intended to be performed) is sensed to beidle before the transmitting entity transmits is deterministic. Category2 may also be known as a Type 2 UL channel access procedure.

Category 3: LBT with random back-off with a contention window of fixedsize. This LBT procedure has the following procedure as one of itscomponents. The transmitting entity draws a random number N within acontention window. The size of the contention window is specified by theminimum and maximum value of N. The size of the contention window isfixed. The random number N is used in the LBT procedure to determine theduration of time that the channel (where transmission is intended to beperformed) is sensed to be idle before the transmitting entity transmitson the channel.

Category 4: LBT with random back-off with a contention window ofvariable size. This LBT procedure has the following as one of itscomponents. The transmitting entity draws a random number N within acontention window. The size of the contention window is specified by theminimum and maximum value of N. The transmitting entity may vary thesize of the contention window when drawing the random number N. Therandom number N is used in the LBT procedure to determine the durationof time that the channel (where transmission is intended to beperformed) is sensed to be idle before the transmitting entity transmitson the channel. Category 4 may also be known as a Type 1 UL channelaccess procedure.

The transmission may be performed by a UE only if the LBT is successful(e.g., explained under each LBT category as shown above). The maximumcontinuous transmission time (upon successful LBT) may be predeterminedby a COT value. LBT may be considered successful if the channel issensed to be idle (e.g., the power detected by a UE, which intends toperform a UL transmission, is less than a predetermined/configured powerthreshold) for a predetermined/configured duration of time during an LBTprocedure (if LBT Category 2/3/4 is performed). On the other hand, LBTmay be considered successful if the UE performs LBT Category 1.Otherwise, LBT failure may be considered not successful. When LBTfailure is considered not successful for a UL transmission, the MACentity may receive an LBT failure indication from PHY.

LCH-based prioritization is introduced in NR Rel-16. An IE (e.g.,lch-BasedPrioritization IE) may be configured for a UE (on a per MACentity basis). If lch-BasedPrioritization IE is configured (e.g., at aMAC entity), the (MAC entity of the) UE may perform LCH-basedprioritization. LCH-based prioritization may also be referred to as onetype of intra-UE prioritization. If a (MAC entity of a) UE is configuredwith lch-BasedPrioritization, the (MAC entity of the) UE may performLCH-based prioritization when two or more UL resources (fully/partially)overlap in the time domain (in the same BWP/cell). A UL resource fromthe two or more UL resources may be a PUSCH resource or a PUCCH resourcefor SR transmission. If two or more UL resources (fully/partially)overlap in the time domain (in the same BWP/cell), the UE may determinea prioritized UL resource from the two or more overlapping UL resourceswith the highest priority, and the other overlapping UL resource(s) thatis not determined as a prioritized UL resource may be referred to as adeprioritized UL resource(s). Subsequently, UL transmission may beperformed on the prioritized UL resource, and may not be performed onthe deprioritized UL resource.

The priority of an uplink resource may be determined by the followingrules (a) and (b).

(a) Priority of a PUSCH resource. If the UL resource is a PUSCHresource, the priority of the UL resource may be the highest priorityamong priorities of the LCHs that are multiplexed (i.e., the MAC PDU totransmit is already stored in the HARQ buffer) or have data availablethat may be multiplexed (i.e., the MAC PDU to transmit is not stored inthe HARQ buffer) in the MAC PDU, according to the LCP mappingrestrictions as described in clause 5.4.3.1.2 of 3GPP TS 38.321, fortransmission on the UL resource.

The priority of a first UL resource, for which no data for LCHs ismultiplexed or may be multiplexed in the MAC PDU for transmission on thefirst UL resource, is lower than the priority of a second UL resource ifdata for any LCHs is multiplexed or may be multiplexed in the MAC PDUfor transmission on the second UL resource.

The priority of a UL resource, for which no data for LCHs is multiplexedor may be multiplexed in the MAC PDU for transmission on the ULresource, is lower than the priority of the LCH triggering an SR.

If the MAC entity is configured with lch-basedPrioritization and ifthere are at least two time-domain overlapping CG PUSCHs whosepriorities are equal, the prioritized CG PUSCH may be determined byUE-specific implementation.

If the MAC entity is configured with lch-basedPrioritization and if afirst PUSCH resource scheduled by a dynamic grant overlaps a second CGPUSCH in the time-domain, the priority of first PUSCH resource may beconsidered as the prioritized PUSCH resource if the priorities of thefirst and second PUSCH resources are the same.

In the present disclosure, the term “priority” may be referred to as“LCH priority”. An LCH priority (e.g., priority IE) associated with anLCH may be configured in the IE that configures the LCH (e.g.,LogicalChannelConfig IE). Moreover, an increasing LCH priority value mayindicate a lower priority. For example, a first LCH associated with anLCH priority value of 1 may have higher priority than a second LCHassociated with an LCH priority value of 2.

(b) Priority of an SR. If the UL resource is a PUCCH resource for SRtransmission, the priority of the UL resource may be the priority of theLCH that triggers the SR.

A Frame based equipment (FBE) is an equipment that may operate in anunlicensed environment. The transmit/receive structure of an FBE has aperiodic timing with a periodicity equal to a fixed frame period (FFP).Two types of devices are defined for FBE operation, where a device thatinitiates a sequence of one or more transmissions is defined as theinitiating device. Otherwise, the device is defined as a respondingdevice.

To initiate a sequence of one or more transmissions, an initiatingdevice may perform a clear channel assessment (CCA) check during asingle observation slot/idle period immediately before startingtransmissions on an operating channel at the start of an FFP. If theoperating channel is found to be clear, the initiating device may startthe transmission immediately. Otherwise, there may be no transmissionson that channel during the next FFP.

An initiating device is allowed to grant an authorization to one or moreassociated responding devices to transmit on the current operatingchannel within the current COT. A responding device may proceed withtransmissions without performing a CCA if it receives a grant and ifthese transmissions are initiated at most 16 μs after the lasttransmission by the initiating device that issued the grant.

A responding device may perform a CCA on the operating channel during asingle observation slot within a 25 μs period ending immediately beforethe granted transmission time which is later than 16 μs after the lasttransmission by the initiating device that issued the grant.

In NR Rel-16 NR-U, gNB may operate as an initiating device. The gNB mayprovide the FFP configuration to a UE via SIB1 or dedicated RRCsignaling (e.g., the UE is configured, by the network,channelAccessMode=Semi StaticChannelAccessConfig via SIB1 or dedicatedRRC signaling). The FFP (e.g., defined by the period IE in theSemiStaticChannelAccessConfig IE) is restricted to values of {1 ms, 2ms, 2.5 ms, 4 ms, 5 ms, 10 ms}. The starting positions of the FFPswithin every two radio frames starts from an even radio frame and aregiven by i*P where i={0, 1, . . . , 20/P-1} where P is the fixed frameperiod in milliseconds. The observation slot/idle period for a givenSCS=ceil (minimum observation slot/idle period allowed byregulations/Ts), where minimum observation slot/idle period allowed=max(5% of FFP, 100 us), and Ts is the symbol duration for the given SCS. UEtransmissions within a fixed frame period may occur if DLsignals/channels (e.g., PDCCH, SSB, PBCH, RMSI, GC-PDCCH, . . . ) withinthe fixed frame period are detected.

A PRACH resource is considered invalid if it overlaps the observationslot/idle period of an FFP when FBE operation is indicated.

With configured uplink grants, the network may allocate UL resources(e.g., PUSCH resources) for the initial HARQ transmissions to UEs viaRRC configuration (and PDCCH). Two types of configured uplink grants aredefined. With Type 1, RRC signaling directly provides the configureduplink grant (including the periodicity). The UL resource (e.g., PUSCHresource) that corresponds to a configured grant Type 1 configuration isconfigured directly by the network via RRC signaling. With Type 2, RRCdefines the periodicity of the configured uplink grant while PDCCHaddressed to CS-RNTI may either signal and activate the configureduplink grant, or deactivate it (e.g., a PDCCH addressed to CS-RNTIindicates that the uplink grant may be implicitly reused according tothe periodicity defined by RRC, until deactivated).

Type 1 and Type 2 are configured by RRC signaling per serving cell andper BWP. Multiple configurations may be active simultaneously only ondifferent serving cells. For Type 2, activation and deactivation areindependent among the serving cells. For the same serving cell, the MACentity is configured with either Type 1 or Type 2.

RRC signaling may configure the following parameters (a)-(e) when theconfigured grant Type 1 is configured:

(a) cs-RNTI: CS-RNTI for retransmission.

(b) periodicity: periodicity of the configured grant Type 1.

(c) timeDomainOffset: Offset of a resource with respect to SFN=0 in thetime domain.

(d) timeDomainAllocation: Allocation of the configured uplink grant inthe time domain which contains startSymbolAndLength (e.g., SLIV in 3GPPTS 38.214).

(e) nrofHARQ-Processes: the number of HARQ processes for the configuredgrant.

Upon configuration of a configured grant Type 1 for a serving cell byupper layers, the MAC entity may (i) store the uplink grant provided byupper layers as a configured uplink grant for the indicated servingcell, and (ii) initialize or re-initialize the configured uplink grantto start in the symbol according to timeDomainOffset and S (derived fromSLIV as specified in 3GPP TS 38.214), and to reoccur with periodicity.

FIG. 1 is a schematic diagram illustrating a configured grant timeroperation in NR, according to an example implementation of the presentdisclosure.

In NR Rel-15, a timer configuredGrantTimer is introduced. The timerconfiguredGrantTimer may be maintained per HARQ process ID. Whenever aUE performs a specific (re-)transmission (e.g., on a resource indicatedby an uplink grant addressed to C-RNTI and the identified HARQ processis configured for a configured uplink grant, on a PUSCH that correspondsto a configured uplink grant (e.g., the CG PUSCH 110), or on a resourceindicated by an uplink grant addressed to the CS-RNTI), aconfiguredGrantTimer that corresponds to the HARQ process ID (e.g., HARQprocess ID=1) of the (re-)transmission is (re)started (e.g., upontransmission on CG PUSCH 110). While configuredGrantTimer thatcorresponds to a HARQ process is running, the UE is prohibited fromperforming a new transmission (e.g., generate a new TB/MAC PDU fortransmission) on a configured uplink grant (e.g., the CG PUSCH 120) ofthe HARQ process ID.

Several new features related to a configured uplink grant (e.g., Feature1-1 to 1-5), as listed below, are introduced in NR Rel-16 NR-U WI toensure the configured uplink grant mechanism may operate smoothly in anunlicensed environment (e.g., shared spectrum) where LBT failure mayoccur. In some implementations, a configured grant configuration mayapply at least one of the features listed below only ifcg-RetransmissionTimer is configured in the configured grantconfiguration (e.g., ConfiguredGrantConfig IE). Thecg-RetransmissionTimer may always be configured in a configured grantconfiguration (e.g., ConfiguredGrantConfig IE) that operates in anunlicensed environment (e.g., shared spectrum). Thecg-RetransmissionTimer may not be configured in a configured grantconfiguration (e.g., ConfiguredGrantConfig IE) that operates in alicensed environment (e.g., licensed spectrum).

Feature 1-1: HARQ process ID selection of a CG PUSCH based on aUE-specific implementation.

The selection of a HARQ process ID for a CG PUSCH may be based on aUE-specific implementation. A UE may select a HARQ process ID for a CGPUSCH among the HARQ process IDs available for the configured grantconfiguration. More specifically, the HARQ process IDs available for theconfigured grant configuration may be determined based on the value oftwo parameters, harq-procID-Offset and nrofHARQ-Processes, as configuredfor the configured grant configuration (e.g., ConfiguredGrantConfig IE).

If both harq-procID-Offset and nrofHARQ-Processes are configured for aconfigured grant configuration (e.g., ConfiguredGrantConfig IE), a UEmay select a HARQ process ID for a CG PUSCH within [harq-procID-Offset,. . . , (harq-procID-Offset+nrofHARQ-Processes−1)].

If only nrofHARQ-Processes is configured for a configured grantconfiguration (e.g., ConfiguredGrantConfig IE), a UE may select a HARQprocess ID for a CG PUSCH within [0, 1, . . . , (nrofHARQ-Processes−1)].

The harq-procID-Offset may always be configured together withcg-RetransmissionTimer in a configured grant configuration (e.g.,ConfiguredGrantConfig IE) that operates in an unlicensed environment(e.g., shared spectrum).

A UE may prioritize retransmissions before initial transmissions whenselecting a HARQ process ID for a CG PUSCH. When selecting a HARQprocess ID of a CG PUSCH via a UE-specific implementation, CG UplinkControl Information (CG-UCI) may be used to indicate the HARQ process IDthat is selected for the CG PUSCH. In some aspects of the presentimplementation, the CG-UCI may be multiplexed on the CG PUSCH. CG-UCImay include HARQ process ID, RV, NDI, and COT information of a CG PUSCH(that the CG-UCI multiplexes with). The UE may toggle the NDI in theCG-UCI for new transmissions and may not toggle the NDI in the CG-UCI inretransmissions.

Feature 1-2: RV selection of a CG PUSCH based on a UE-specificimplementation.

A UE may select an RV of a CG PUSCH based on a UE-specificimplementation. The CG PUSCH may be for initial transmission or forretransmission (e.g., repetition).

Feature 1-3: Autonomous retransmission of a MAC PDU/TB on a CG PUSCH.FIG. 2 is a schematic diagram illustrating an operation of the CG timer(e.g., cg-RetransmissionTimer), according to an example implementationof the present disclosure.

When a UE fails to transmit a generated MAC PDU/TB on a first CG PUSCH(e.g., CG PUSCH 1 as represented by 210 in FIG. 2), the UE may performautonomous retransmission on a second CG PUSCH (e.g., CG PUSCH 2 asrepresented by 220 in FIG. 2) if at least one of the followingconditions (e.g., from Condition A1 through Condition A6) is satisfied.The UE may fail to transmit a MAC PDU/TB due to LBT failure (e.g., theUE senses the channel to be busy, the UE receives an LBT failureindication, etc.). The UE may consider the NDI bit as “not toggled” whenit determines to perform autonomous retransmission on a second CG PUSCH(e.g., CG PUSCH 2 as represented by 220 in FIG. 2).

Condition A1: The TBS of the first CG PUSCH (e.g., CG PUSCH 1 asrepresented by 210 in FIG. 2) is the same as the TBS of the second CGPUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2).

Condition A2: The first CG PUSCH (e.g., CG PUSCH 1 as represented by 210in FIG. 2) and the second CG PUSCH (e.g., CG PUSCH 2 as represented by220 in FIG. 2) have the same HARQ process ID (e.g., HARQ process ID=i).

Condition A3: The configured grant configuration(s) that the first CGPUSCH (e.g., CG PUSCH 1 as represented by 210 in FIG. 2) and the secondCG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2) correspondto are configured in the same BWP. The configured grant configuration(s)that corresponds to the first CG PUSCH (e.g., CG PUSCH 1 as representedby 210 in FIG. 2) and the second CG PUSCH (e.g., CG PUSCH 2 asrepresented by 220 in FIG. 2) may or may not be the same. However, theyneed to be configured in the same BWP.

Condition A4: The network has not provided a dynamic grant forretransmission of the first CG PUSCH (e.g., CG PUSCH 1 as represented by210 in FIG. 2). The dynamic grant for retransmission of the first CGPUSCH (e.g., CG PUSCH 1 as represented by 210 in FIG. 2) may have thesame HARQ process ID as the first CG PUSCH (e.g., CG PUSCH 1 asrepresented by 210 in FIG. 2). If the network has provided a dynamicgrant (e.g., a UL grant associated with C-RNTI or CS-RNTI) forretransmission of the first CG PUSCH (e.g., CG PUSCH 1 as represented by210 in FIG. 2) before the second CG PUSCH (e.g., CG PUSCH 2 asrepresented by 220 in FIG. 2) becomes available, the second CG PUSCH(e.g., CG PUSCH 2 as represented by 220 in FIG. 2) may not be used forautonomous retransmission.

Condition A5: The cg-RetransmissionTimer that corresponds to the HARQprocess ID of the first (and second) PUSCH is not running. Thecg-RetransmissionTimer may be configured per HARQ process ID. It may beused to prohibit a UE from performing immediate autonomousretransmission on a CG PUSCH. The UE may only perform retransmission ona CG PUSCH if the cg-RetransmissionTimer for the HARQ process of the CGPUSCH is not running.

The cg-RetransmissionTimer of a HARQ process may be (re)started whentransmission (e.g., new transmission or retransmission) on a configureduplink grant of the HARQ process is performed successfully (e.g., the UEdoes not receive an LBT failure indication for the correspondingtransmission). For example, in FIG. 2, the cg-RetransmissionTimer for aHARQ process (e.g., HARQ ID=i) of CG PUSCH 1 may be (re)started whentransmission of a TB on CG PUSCH 1 is performed successfully.Subsequently, the UE may retransmit the TB for CG PUSCH 1 on CG PUSCH 2when the cg-RetransmissionTimer for the HARQ process of CG PUSCH 1 isstopped or is not running. In some implementations, thecg-RetransmissionTimer of a HARQ process may be stopped when the UEreceives DFI for the corresponding HARQ process. In someimplementations, the cg-RetransmissionTimer of a HARQ process may bestopped when the UE receives a dynamic grant (e.g., a UL grantassociated with C-RNTI or CS-RNTI) for the HARQ process. In someimplementations, the cg-RetransmissionTimer of a HARQ process may bestopped when the configuredGrantTimer for the HARQ process expires. Insome implementations, the cg-RetransmissionTimer of a HARQ process maybe stopped when a configured grant Type 2 activation command is receivedfor a configured grant configuration that the HARQ process correspondsto.

Condition A6: The second CG PUSCH (e.g., CG PUSCH 2 as represented by220 in FIG. 2) is for retransmission.

The UE may only perform autonomous transmission on the second CG PUSCHonly if the second CG PUSCH (e.g., CG PUSCH 2 as represented by 220 inFIG. 2) is for retransmission.

The second CG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2)may be considered for retransmission if the configuredGrantTimer for theHARQ process ID of the second CG PUSCH (e.g., CG PUSCH 2 as representedby 220 in FIG. 2) is running and the cg-RetransmissionTimer for the HARQprocess of the second CG PUSCH (e.g., CG PUSCH 2 as represented by 220in FIG. 2) is configured and not running.

The second CG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2)may be considered for retransmission if the configuredGrantTimer for theHARQ process ID of the second CG PUSCH (e.g., CG PUSCH 2 as representedby 220 in FIG. 2) is running, the cg-RetransmissionTimer for the HARQprocess of the second CG PUSCH (e.g., CG PUSCH 2 as represented by 220in FIG. 2) is configured and not running, and the HARQ process of thesecond CG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2) ispending/not pending.

The second CG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2)may be considered for retransmission if the configuredGrantTimer for theHARQ process ID of the second CG PUSCH (e.g., CG PUSCH 2 as representedby 220 in FIG. 2) is running/not running, the cg-RetransmissionTimer forthe HARQ process of the second CG PUSCH (e.g., CG PUSCH 2 as representedby 220 in FIG. 2) is configured and not running, and the HARQ process ofthe second CG PUSCH (e.g., CG PUSCH 2 as represented by 220 in FIG. 2)is pending.

Feature 1-4: DFI transmission from the network

A UE may be expected to receive DFI from the network. DFI may beindicated via a DCI format 0_1 with CRC scrambled by CS-RNTI). When a UEreceives a DCI format 0_1 with CRC scrambled by CS-RNTI, the UE mayidentify that the received DCI is DFI if the (1-bit) DFI flag in the DCIindicates a value of 1. The DFI flag in a DCI format 0_1 may be either0-bit or 1-bit. The DFI flag is 1 bit if the UE is configured to monitorDCI format 0_1 with CRC scrambled by CS-RNTI and for operation in a cellwith shared spectrum channel access.

DFI may include a (16-bit) HARQ-ACK bitmap, where the order of thebitmap to HARQ process index mapping is such that HARQ process indicesare mapped in ascending order from MSB to LSB of the bitmap. For eachbit of the bitmap, value 1 indicates ACK, and value 0 indicates NACK.

A cg-minDFI-Delay IE may be configured for a configured grantconfiguration (e.g., ConfiguredGrantConfig IE). When configured in aconfigured grant configuration (e.g., ConfiguredGrantConfig IE), thecg-minDFI-Delay IE may indicate the minimum duration (in unit ofsymbols) from the ending symbol of a CG PUSCH to the starting symbol ofthe PDCCH containing the DFI carrying HARQ-ACK for this CG PUSCH. TheHARQ-ACK received before this minimum duration may not be considered asvalid for this CG PUSCH.

The cg-RetransmissionTimer of a HARQ process may be stopped when the UEreceives (valid) DFI for the corresponding HARQ process. TheconfiguredGrantTimer of a HARQ process may be stopped when the UEreceives (valid) DFI indicating ACK for the corresponding HARQ process.

Feature 1-5: UE behavior upon LBT failure.

If a CG PUSCH is not successfully transmitted due to LBT failure, theconfiguredGrantTimer that corresponds to the HARQ process ID of the CGPUSCH is not (re)started. If a CG PUSCH is not successfully transmitteddue to LBT failure, the cg-RetransmissionTimer that corresponds to theHARQ process of the CG PUSCH is not (re)started.

A configuredGrantTimer that corresponds to a HARQ process ID is only(re)started if an LBT failure indication is not received from PHY whentransmission is performed (e.g., successful transmission) for the HARQprocess. A cg-RetransmissionTimer that corresponds to a HARQ process IDis only (re)started if an LBT failure indication is not received fromPHY when transmission is performed (e.g., successful transmission) forthe HARQ process.

A device that supports NR Rel-16 IIoT/URLLC features may be operatedunder a licensed spectrum (e.g., a licensed carrier/cell). Several newfeatures related to configured uplink grant (e.g., Features 2-1 to 2-4),as listed below, are introduced in NR Rel-16 IIoT/URLLC WI to ensure theconfigured uplink grant mechanism may meet the reliability and delayrequirement of IIoT/URLLC traffic. A configured grant configuration mayapply at least one of the features listed below only ifcg-RetransmissionTimer is not configured in the configured grantconfiguration (e.g., ConfiguredGrantConfig IE). Thecg-RetransmissionTimer may not be configured in a configured grantconfiguration (e.g., ConfiguredGrantConfig IE) that operates in alicensed environment (e.g., licensed spectrum).

Feature 2-1: HARQ process ID selection of a CG PUSCH based on apredefined equation.

For a configured grant configuration that is neither configured withharq-ProcID-Offset2 nor with cg-RetransmissionTimer (e.g., neitherharq-ProcID-Offset2 nor with cg-RetransmissionTimer is configured inConfiguredGrantConfig IE of the configured grant configuration), theHARQ process ID associated with the first symbol of a CG PUSCH may bederived from Predefined Equation 1.

HARQ process ID=[floor (CURRENT symbol/periodicity)]modulonrofHARQ-Processes  Predefined Equation 1:

For a configured grant configuration that is configured withharq-ProcID-Offset2 (e.g., harq-ProcID-Offset2 is configured inConfiguredGrantConfig IE of the configured grant configuration), theHARQ process ID associated with the first symbol of a CG PUSCH may bederived from Predefined Equation 2.

HARQ process ID=[floor (CURRENT symbol/periodicity)]modulonrofHARQ-Processes+harq-ProcID-Offset2  Predefined Equation 2:

More specifically, CURRENTsymbol=(SFN×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+slot number inthe frame×numberOfSymbolsPerSlot+symbol number in the slot), andnumberOfSlotsPerFrame and numberOfSymbolsPerSlot refer to the number ofconsecutive slots per frame and the number of consecutive symbols perslot, respectively, as specified in 3GPP TS 38.211. Ifcg-RetransmissionTimer is not configured, a HARQ process is not sharedbetween different configured grant configurations in the same BWP. Theharq-ProcID-Offset2 may not be configured simultaneously withcg-RetransmissionTimer in the same configured grant configuration (e.g.,ConfiguredGrantConfig IE).

Feature 2-2: RV selection of a CG PUSCH based on configuration.

The RV of a CG PUSCH may be selected based on repk-RV configured in theconfigured grant configuration (e.g., configuredGrantConfig IE) that theCG-PUSCH corresponds to. The parameter repK-RV defines the redundancyversion pattern to be applied to the repetitions. If neither repK-RV norcg-RetransmissionTimer is provided in a configured grant configuration(e.g., configuredGrantConfig IE), the RV for CG PUSCH corresponding tothe configured grant configuration may be set to 0. The parameterrepK-RV and cg-RetransmissionTimer may not be configured in the sameconfigured grant configuration (e.g., configuredGrantConfig IE).

Feature 2-3: Autonomous transmission of a MAC PDU/TB on a CG PUSCH.

When a UE fails to transmit a generated MAC PDU/TB on a first CG PUSCH,the UE may perform autonomous transmission on a second CG PUSCH if (atleast one of) the following conditions (e.g., from Condition B1 throughCondition B6) are satisfied. Specifically, the UE may fail to transmit aMAC PDU/TB due to the first PUSCH being deprioritized (e.g., the firstCG PUSCH is considered as a deprioritized CG PUSCH) as a result ofintra-UE prioritization (e.g., LCH-based prioritization).

Condition B1: The TBS of the first CG PUSCH is the same as the TBS ofthe second CG PUSCH.

Condition B2: The first CG PUSCH and the second CG PUSCH correspond tothe same configured grant configuration in the same BWP.

Condition B3: The first CG PUSCH and the second CG PUSCH have the sameHARQ process ID.

The second CG PUSCH, which has the same HARQ process ID as the first CGPUSCH, may be the CG PUSCH that becomes available first (e.g., that a UEreceives first) after the first CG PUSCH.

Condition B4: The network has not provided a dynamic grant forretransmission of the first CG PUSCH.

The dynamic grant for retransmission of the first CG PUSCH may have thesame HARQ process ID as the first CG PUSCH. If the network has provideda dynamic grant (e.g., a UL grant associated with C-RNTI or CS-RNTI) forretransmission of the first CG PUSCH before the second CG PUSCH becomesavailable, the second CG PUSCH may not be used for autonomousretransmission.

Condition B5: autonomousTx has been configured in the configured grantconfiguration (e.g., configuredGrantConfig IE) that the second CG PUSCH(and the first CG PUSCH) corresponds to.

The UE may perform autonomous transmission on the second CG PUSCH onlyif autonomousTx is configured for the configured grant configurationthat the second CG PUSCH corresponds to. Moreover, the second CG PUSCHmay be used for performing a new transmission. For example, the UE mayperform autonomous transmission on the second CG PUSCH only if theconfiguredGrantTimer associated with the HARQ process ID of the secondCG PUSCH is not running.

Condition B6: The second CG PUSCH is for new transmission (e.g., initialtransmission).

The UE may perform autonomous transmission on the second CG PUSCH onlyif the second CG PUSCH is for new transmission. The second CG PUSCH maybe considered for new transmission (e.g., initial transmission) if theconfiguredGrantTimer for the HARQ process ID of the second CG PUSCH isnot running and the cg-RetransmissionTimer for the HARQ process of thesecond CG PUSCH is not configured. The second CG PUSCH may be consideredfor new transmission (e.g., initial transmission) if theconfiguredGrantTimer for the HARQ process ID of the second CG PUSCH isnot running, the cg-RetransmissionTimer for the HARQ process of thesecond CG PUSCH is configured and not running, and the HARQ process IDof the second CG PUSCH is not considered as pending.

Feature 2-4: UE behavior when a MAC PDU/TB is deprioritized.

If a CG PUSCH is not successfully transmitted due the CG PUSCH beingdeprioritized, the configuredGrantTimer that corresponds to the HARQprocess ID of the CG PUSCH is not (re)started.

Note that a UCE may be referred to as an unlicensed environment withcontrolled deployment. Therefore, interference from other systems usingdifferent radio access technology is not expected or only sporadicallyhappens. An example of a UCE may be a factory with equipment (e.g.,robots, actuators, sensors, etc.) that operates in an unlicensedband/carrier. Moreover, the equipment may be deployed in a specificmanner such that they do not cause interference with one another.However, even with proper deployment, channel access (e.g., LBT/CCA) maystill be required by an equipment (e.g., UE, gNB, etc.) beforeperforming a transmission. This implies that LBT failure may still occurin a UCE.

To support URLLC/IIoT services over a UCE in NR Rel-17, someconfiguration restrictions have been lifted, given the fact that thechannel condition in a UCE is relatively stable than in other unlicensedenvironments. Some new configuration features (e.g., Feature 3-1 toFeature 3-3) may be introduced below.

Feature 3-1: cg-RetransmissionTimer may be configured optionally forshared spectrum.

For instance, in NR Rel-16, cg-RetransmissionTimer IE always needs to beconfigured for shared spectrum. However, in NR Rel-17,cg-RetransmissionTimer IE may be configured optionally for sharedspectrum. Moreover, when cg-RetransmissionTimer IE is not configured (inan FBE that operates in shared spectrum), the NR Rel-16 URLLC/IIoTmechanism may be used for HARQ process ID and RV selection. That is tosay, when cg-RetransmissionTimer IE is not configured, the UE may derivea HARQ process ID of a CG PUSCH based on a predefined equation (e.g.,Predefined Equation 1 or Predefined Equation 2). Moreover, whencg-RetransmissionTimer IE is not configured, the UE may derive an RV ofa CG PUSCH based on a configuration (defined in Feature 2-2).

On the contrary, when cg-RetransmissionTimer IE is configured (in an FBEthat operates in shared spectrum), the NR Rel-16 NR-U mechanism may beused for HARQ process ID and RV selection. That is to say, whencg-RetransmissionTimer IE is configured, the UE may derive a HARQprocess ID and RV of a CG PUSCH based on a UE-specific implementation.

Feature 3-2: cg-RetransmissionTimer IE may be configured together withautonomousTx IE.

The assumption in NR Rel-16 is the network does not configureautonomousTx and cg-RetransmissionTimer simultaneously per cell.However, such a restriction may be lifted in NR Rel-17. Moreover, ifboth autonomousTx and cg-RetransmissionTimer are configured (in aserving cell), autonomousTx and cg-Retransmission may be used to handledeprioritized MAC PDU and LBT-failed MAC PDU, respectively. In otherwords, if a MAC PDU was not transmitted on a CG PUSCH due to the CGPUSCH being deprioritized (as a result of intra-UE prioritization), theMAC PDU may be transmitted on another CG resource (for new transmission)only if autonomousTx is configured. On the other hand, if a MAC PDU thatwas not transmitted on a CG PUSCH due to LBT failure, the MAC PDU may beretransmitted on another CG PUSCH (for retransmission) only ifcg-RetransmissionTimer is configured.

Feature 3-3: cg-RetransmissionTimer IE may be configured together withlch-BasedPrioritization IE.

The cg-RetransmissionTimer IE may be configured together withlch-BasedPrioritization IE in the same serving cell to supportIIoT/URLLC in a UCE in NR Rel-17.

One of the core objectives of NR Rel-17 WI on enhanced IndustrialInternet of Things (IoT) and URLLC support is to ensure Rel-16 featurecompatibility with unlicensed band URLLC/IIoT operation in controlledenvironments. Particularly, UL enhancements for IIoT/URLLC in UCEs maybe studied. This includes harmonizing UL configured grant enhancementsin NR-U and IIoT/URLLC introduced in Rel-16 to be applicable forunlicensed spectrum.

Note that a UCE may be referred to as an unlicensed environment withcontrolled deployment. Therefore, interference from other systems usingdifferent radio access technology is not expected or only sporadicallyhappens. An example of a UCE may be a factory with equipment (e.g.,robots, actuators, sensors, etc.) that operates in an unlicensedband/carrier. Moreover, the equipment may be deployed in a specificmanner such that they do not cause interference with one another.However, even with proper deployment, channel access (e.g., LBT/CCA) maystill be required by an equipment (e.g., UE, gNB, etc.) beforeperforming a transmission. This implies that LBT failure may still occurin a UCE.

Based on the objective of NR Rel-17 WI of enhanced Industrial Internetof Things (eIIoT) and URLLC support, a new mechanism may be required toharmonize mechanisms/schemes introduced in Rel-16 NR-U WI and Rel-16IIoT/URLLC WI. Hence, some configuration restrictions have been lifted,and some new configuration combinations (e.g., new IE combinations) havebeen allowed in order to support such harmonization. The presentdisclosure discusses the potential issues associated with the newconfiguration combinations (e.g., new IE combinations). Relevantsolutions are also presented to resolve the identified issues.

FIG. 3 is a schematic diagram illustrating an issue associated with theautonomous transmission of a deprioritized MAC PDU, according to anexample implementation of the present disclosure.

In NR Rel-17, autonomousTx, cg-RetransmssionTimer andlch-BasedPrioritization may be configured in the same serving cell/CGconfiguration/MAC entity. Intra-UE prioritization may occur (e.g.,PHY-based prioritization and/or LCH-based prioritization) when two ormore UL resources overlap in the time domain and/or when a UL resourceis preempted by CI-RNTI. As a result of intra-UE prioritization, the UEmay determine one prioritized UL resource out of the time-domainoverlapping UL resources for transmission. Moreover, the UE maydetermine the UL resource(s) that overlaps the prioritized UL resourceas a deprioritized UL resource(s). In the case that a deprioritized ULresource is a CG PUSCH, e.g., CG PUSCH 1 (as represented by 310) in FIG.3, from a CG configuration configured with autonomousTx, the intendedbehavior may be to autonomously transmit a first MAC PDU, which wasgenerated but was unable to be transmitted on CG PUSCH 1, on the nextavailable CG PUSCH, e.g., CG PUSCH 2 (as represented by 320) in FIG. 3,with the same HARQ process ID. However, if cg-RetransmssionTimer isconfigured at the CG configuration that CG PUSCH 2 corresponds to, itmay be up to a UE-specific implementation to select a HARQ process IDamong the HARQ process IDs available for the configured grantconfiguration that CG PUSCH 2 corresponds to. Moreover, the UE mayprioritize the HARQ process ID(s) for retransmission(s) over HARQprocess ID(s) for new/initial transmission(s) when selecting a HARQprocess ID of CG PUSCH 2. This behavior may delay the transmission ofthe first MAC PDU because the HARQ process ID of the first MAC PDU maybe considered as a HARQ process ID for new transmission, i.e., theconfiguredGrantTimer and cg-RetransmissionTimer for the HARQ process IDof the first MAC PDU may not be running and/or the HARQ process ID ofthe first MAC PDU may not be considered as pending when CG PUSCH 2becomes available. As a result, HARQ process ID of the first MAC PDU maybe deprioritized when there is at least one HARQ process ID forretransmission from the CG configuration that CG PUSCH 2 corresponds to.

The HARQ process ID of the first MAC PDU may also be referred to as theHARQ process ID of CG PUSCH 1. CG PUSCH 1 and CG PUSCH 2 may have thesame HARQ process ID and/or TBS. CG PUSCH 1 and CG PUSCH 2 maycorrespond to the same/different CG configuration. Iflch-BasedPrioritization is configured at a UE, LCH-based prioritizationmay be performed by the UE when CG PUSCH 1 overlaps another UL resource(e.g., PUSCH, PUCCH, etc.) in the time domain (in the same servingcell). This may result in CG PUSCH 1 being deprioritized.

To not delay the autonomous transmission of a deprioritized MAC PDU, theUE may conditionally prioritize a HARQ process ID(s) for newtransmission over HARQ process ID(s) for retransmission. Severalsolutions are proposed in the present disclosure.

In some implementations, when a UE needs to select a HARQ process ID ofa CG PUSCH, the UE may prioritize the HARQ process ID for newtransmission (e.g., initial transmission) over the HARQ process ID forretransmission when at least one of the following conditions issatisfied. In some implementations, the UE may enable a first HARQprocess ID selection procedure to select a HARQ process ID of a CGPUSCH, when at least one of the following conditions is satisfied (e.g.,when Condition 1-2 described below is satisfied). In contrast, the UEmay enable a second HARQ process ID selection procedure to select theHARQ process ID of the CG PUSCH when at least one of the followingconditions is not satisfied (e.g., when Condition 1-2 is not satisfied).The definition of the first HARQ process ID selection procedure and thesecond HARQ process ID selection procedure are described in the presentdisclosure. In some implementations, when at least one of the followingconditions is satisfied (e.g., when Condition 1-2 is satisfied), the UEmay determine whether to prioritize the HARQ process ID for newtransmission over the HARQ process ID for retransmission based onwhether the priority of the HARQ process ID for new transmission ishigher than the priority of the HARQ process ID for retransmission. Insome implementations, the UE may prioritize the HARQ process ID for newtransmission over the HARQ process ID for retransmission when at leastone of the following conditions is satisfied (e.g., when Condition 1-2is satisfied) and the priority of the HARQ process ID for newtransmission is higher than the priority of the HARQ process ID forretransmission. FIG. 4 is a flowchart illustrating a method forselecting a HARQ process ID of a CG PUSCH, according to an exampleimplementation of the present disclosure. In action 402, a CG PUSCHbecomes available for transmission, and the CG configuration that the CGPUSCH corresponds to is configured with cg-RetransmissionTimer In action404, the UE may determine to select a HARQ process ID of the CG PUSCHdue to the cg-RetransmissionTimer being configured. For example, theHARQ process ID of the CG PUSCH may be selected among the HARQ processIDs available for the configured grant configuration that the CG PUSCHcorresponds or belongs to. In action 406, the UE may further determinewhether to (allow) prioritize the HARQ process ID(s) of initialtransmission (e.g., a new transmission) over the HARQ process ID(s) ofretransmission when selecting the HARQ process ID of the CG PUSCH, andvice versa, based on at least one of Condition 1-1 to Condition 1-3,described below.

When at least one of Condition 1-1 to Condition 1-3 is satisfied, the UEmay perform action 408 and may prioritize the HARQ process ID(s) of newtransmission (e.g., initial transmission) over the HARQ process ID(s) ofretransmission when selecting a HARQ process ID of the CG PUSCH. On theother hand, when at least one of Condition 1-1 to Condition 1-3 is notsatisfied, the UE may perform action 410 and may prioritize the HARQprocess ID(s) of retransmission over the HARQ process ID(s) of newtransmission (e.g., initial transmission) when selecting a HARQ processID of the CG PUSCH. In action 410, the UE may set the HARQ process ID ofthe CG PUSCH to the selected HARQ process ID.

In some implementations, if a UE determines to prioritize the HARQprocess ID(s) of initial transmission over the HARQ process ID(s) ofretransmission when selecting a HARQ process ID of a CG PUSCH (e.g.,action 408), the UE may select a HARQ process ID among the HARQ processID(s) of the configured grant configuration that the CG PUSCHcorresponds or belongs to and for which is available for initialtransmission, if any. On the other hand, if there is no HARQ processID(s) available for initial transmission from the configured grantconfiguration that the CG corresponds or belongs to, the UE may select aHARQ process ID among the HARQ process ID(s) for retransmission for theconfigured grant configuration that the CG PUSCH corresponds or belongsto.

Condition 1-1: The UE has at least one HARQ process ID that correspondsto a deprioritized MAC PDU and/or the UE does not have any HARQ processID that corresponds to a pending MAC PDU.

When a UE needs to select a HARQ process ID for a CG resource, and theUE has at least one HARQ process that corresponds to a deprioritized PDUand/or the UE does not have any HARQ process ID that corresponds to apending PDU, the UE may prioritize the HARQ process ID for newtransmission (e.g., initial transmission) over the HARQ process ID forretransmission. Otherwise, the UE may prioritize the HARQ process ID forretransmission over the HARQ process ID for new transmission.

Condition 1-2: The UE has been configured with at least one IE from IECategory 1.

When a UE needs to select a HARQ process of a CG resource, and the CGresource corresponds to a CG configuration configured with bothcg-RetransmissionTimer and autonomousTx, and the UE has at least oneHARQ process ID corresponding to a deprioritized MAC PDU (for the CGconfiguration), the UE may prioritize the HARQ process ID for newtransmission over the HARQ process ID for retransmission (e.g., enablinga first HARQ process ID selection procedure) when selecting a HARQprocess ID for the CG configuration. Otherwise, the UE may prioritizethe HARQ process ID for retransmission over the HARQ process ID for newtransmission (e.g., enabling a second HARQ process ID selectionprocedure) when selecting a HARQ process ID for the CG configuration.

Condition 1-3: The priority level of a HARQ process ID forretransmission is lower than the priority level of a HARQ process ID forinitial transmission.

The priority level of a HARQ process ID for initial transmission may bedetermined by the highest priority among priorities of the MAC CEsand/or LCHs with data available that may be multiplexed/generated in aMAC PDU to be transmitted on the CG PUSCH and/or the highest priorityamong priorities of the MAC CEs and/or data from a deprioritized (and/orpending) MAC PDU(s) that may be autonomously transmitted on the CGPUSCH.

The priority of a MAC CE may be determined by thepriority/channelAccessPriority IE configured for the MAC CE. Thepriority of an LCH may be determined by thepriority/channelAccessPriority IE configured for the LCH. An increasingpriority value may indicate a lower priority level. The priority valueof an LCH may be configured in the IE that configures the parameters ofthe LCH (e.g., LogicalChannelConfig IE). The UE may consider the mappingrestriction of the MAC CE(s) and/or LCH(s) when multiplexing/generatinga MAC PDU using available data from an LCH and/or MAC CE. In this sense,the priority level of the MAC CEs and/or LCHs that do not satisfy themapping restriction of the CG PUSCH need not be considered. Thedeprioritized/pending MAC PDU may have already been obtained/generatedand stored in the HARQ buffer associated with the CG PUSCH. Moreover,the priority of data from a deprioritized/pending MAC PDU may bedetermined by the priority/channelAccessPriority IE configured for theLCH where the data comes from. The deprioritized/pending MAC PDU may beintended for transmission on another CG PUSCH that arrives earlier thanthe PUSCH. The deprioritized/pending MAC PDU(s) has not yet beenacknowledged by the network and may be retransmitted on the CG PUSCH.Here, the HARQ process ID(s) of the deprioritized/pending MAC PDU(s) maybe referred to as the HARQ process ID(s) of new transmission.

The priority level of a HARQ process ID for retransmission may bedetermined by the highest priority among priorities of the MAC CEsand/or data from a pending (and/or deprioritized) MAC PDU(s) that may beretransmitted on the CG PUSCH. The deprioritized/pending MAC PDU mayhave already been obtained/generated and stored in the HARQ bufferassociated with the CG PUSCH. Moreover, the priority of data from adeprioritized/pending MAC PDU may be determined by thepriority/channelAccessPriority IE configured for the LCH where the datacomes from. The pending/deprioritized MAC PDU may be intended fortransmission on another CG PUSCH that arrives earlier than the PUSCH.The pending/deprioritized MAC PDU(s) has not yet been acknowledged bythe network and may be retransmitted on the CG PUSCH. Here, the HARQprocess ID(s) of the pending/deprioritized MAC PDU(s) may be referred toas the HARQ process ID(s) of retransmission.

If the HARQ process ID for initial transmission corresponds to at leastone deprioritized PDU and/or the HARQ process ID for retransmission doesnot correspond to any pending PDU, the HARQ process ID for initialtransmission may be considered as having the highest priority leveland/or the HARQ process for retransmission may be considered as havingthe lowest priority level.

If the HARQ process ID for initial transmission does not correspond toany deprioritized PDU and/or the HARQ process ID for retransmissioncorresponds to at least one pending PDU, the HARQ process ID forretransmission may be considered as having the highest priority leveland/or the HARQ process for initial transmission may be considered ashaving the lowest priority level.

If the priority level of the HARQ process ID for retransmission is equalto the priority level of the HARQ process ID for new transmission, theUE may prioritize the HARQ process ID of retransmission over the HARQprocess ID for new transmission when selecting a HARQ process ID of theCG resource.

If the priority level of the HARQ process ID for retransmission is equalto the priority level of the HARQ process ID for new transmission, theUE may prioritize the HARQ process ID of new transmission over the HARQprocess ID for retransmission when selecting a HARQ process ID of the CGresource.

In one implementation, when a UE selects a HARQ process ID, the UE mayprioritize the HARQ process ID that corresponds to a deprioritized MACPDU over the HARQ process ID for new transmission (e.g., initialtransmission) and/or the HARQ process ID for retransmission.Alternatively, the UE may prioritize the HARQ process ID of a pendingMAC PDU over the HARQ process ID of new transmission (e.g., initialtransmission) and/or the HARQ process ID of retransmission.

When a UE selects a HARQ process ID of a CG PUSCH, the UE behavior asdefined in the implementations in the present section (and/or thepresent disclosure) may only be applied if at least one of the IEs fromIE Category 1 is configured. Otherwise, the UE may follow 3GPP TS 38.321to prioritize HARQ process ID(s) of retransmission(s) over HARQ processID(s) of new/initial transmission(s) when selecting a HARQ process ID ofthe CG PUSCH.

The specific IE from IE Category 1 may be configured per HARQ process,CG configuration, BWP, serving cell, and/or Cell Group (e.g., MACentity). The specific IE from IE Category 1 may be used for enablingCG-UCI transmission. The specific IE from IE Category 1 may be used forenabling DFI reception. If the specific IE from IE Category 1 isconfigured, the UE may always prioritize the HARQ process correspondingto a deprioritized/pending MAC PDU over other HARQ process IDs for newtransmission/retransmission.

IE Category 1 may include the following IEs, e.g.,cg-RetransmissionTimer, configuredGrantTimer,configuredGrantConfigIndex, configuredGrantConfigIndexMAC,ConfiguredGrantConfigToAddModList, autonomousTx, phy-PriorityIndex,allowedCG-List, lch-BasedPrioritization, harq-ProcID-Offset,harq-ProcID-Offset2, lbt-FailureRecoveryConfig, repK-RV, and a specificIE.

In some implementations, when a CG PUSCH becomes available fortransmission and a UE needs to select a HARQ process ID for the CGPUSCH, the UE may follow 3GPP TS 38.321 and prioritize the HARQ processID for retransmission over the HARQ process ID for new transmission. Inthe present implementation, the UE may consider a HARQ process IDcorresponding to a deprioritized MAC PDU as a HARQ process ID forretransmission. Please note that if a HARQ process ID corresponding to adeprioritized MAC PDU is considered for retransmission, the (MAC entityof the) UE may consider the NDI for the HARQ process ID that correspondsto the deprioritized MAC PDU to not have been toggled. As a result, ifthe deprioritized MAC PDU is transmitted on the CG PUSCH, and CG-UCIindicating the HARQ process ID of the CG PUSCH needs to be transmitted,the UE may not toggle the NDI value in the CG-UCI if a deprioritized PDUis transmitted on the CG PUSCH.

If a UE determines a CG PUSCH as a deprioritized CG PUSCH, the UE maystop the configuredGrantTimer and/or cg-RetransmissionTimer associatedwith the HARQ process of the CG PUSCH if the CG PUSCH is configured withautonomousTx.

The autonomousTx may be considered as being configured in the UL CGPUSCH if it is configured in the configuredGrantConfig IE thatconfigures the CG PUSCH. The configuredGrantTimer and/orcg-RetransmissionTimer may be configured in the CG PUSCH resource.Please note that configuredGrantTimer/cg-RetransmissionTimer isconsidered as being configured in the CG PUSCH if it is configured inthe configuredGrantConfig IE that configures the CG PUSCH. TheconfiguredGrantTimer/cg-RetransmissionTimer may be stopped if it isrunning. The UE may determine the CG PUSCH as a deprioritized CG PUSCHafter performing LCH-based prioritization. In this case, the (MAC entityof the) UE may need to be configured with lch-basedPrioritization inorder to perform LCH-based prioritization.

The UE may determine the CG PUSCH as a deprioritized CG PUSCH if it iscancelled by a high PHY-priority UL transmission (e.g., PUCCHtransmission as specified in clause 9 of 3GPP TS 38.213). For example,when a CG PUSCH partially/fully overlaps a UL transmission in the timedomain (in the same serving cell), the UE may perform a PHY-basedintra-UE prioritization procedure. During the PHY-based intra-UEprioritization procedure, the UE may compare the PHY-priority of the CGPUSCH and the PHY-priority of the UL transmission. For example, the UEmay compare the value of the phy-PriorityIndex of the CG PUSCH with thephy-PriorityIndex of the UL transmission. If the CG PUSCH has lowerPHY-priority than the UL transmission, the CG PUSCH may be determined asa deprioritized CG PUSCH, and the UL transmission may be determined as aprioritized UL transmission. Consequently, the deprioritized CG PUSCHmay be considered as being cancelled by the prioritized UL transmission.The PHY-priority (e.g., phy-PriorityIndex) of the CG PUSCH may beconfigured in the CG configuration (e.g., configuredGrantConfig IE) thatthe CG PUSCH corresponds to. The PHY-priority may have two values: afirst value (e.g., p1) indicates a high priority and a second value(e.g., p2) indicates low priority.

The UE may determine the CG PUSCH as a deprioritized CG PUSCH may becancelled by a CI-RNTI as specified in clause 11.2A of 3GPP TS 38.213.

FIG. 5 is a schematic diagram illustrating another issue associated withthe autonomous transmission of a deprioritized MAC PDU, according to anexample implementation of the present disclosure. An exemplary scenarioin FIG. 5 may occur at a UE based on the abovementioned issue statement.Please note that in FIG. 5, configuredGrantTimer andcg-RetransmissionTimer are denoted as CG timer and CGRT timer,respectively. In FIG. 5, a UE is configured with a CG configuration(e.g., CG configuration 1). At least one of autonomousTx,configuredGrantTimer, and cg-RetransmissionTimer may be configured inthe CG configuration (e.g., CG configuration 1). Moreover, CG PUSCH 1(represented by 510 in FIG. 5), CG PUSCH 2 (represented by 520 in FIG.5), and CG PUSCH 3 (represented by 530 in FIG. 5) may correspond to theCG configuration (e.g., CG configuration 1). If the UE successfullytransmits a first MAC PDU on CG PUSCH 1 that corresponds with a HARQprocess ID of 1 and an NDI value of 1, the UE may (re)startconfiguredGrantTimer associated with HARQ process ID of 1 and (re)startcg-RetransmissionTimer associated with HARQ process ID of 1 (e.g., atthe beginning of the transmission on CG PUSCH 1). Subsequently,cg-RetransmissionTimer may be expired/stopped before CG PUSCH 2 becomesavailable. Since configuredGrantTimer of HARQ process ID 1 is runningand cg-RetransmissionTimer is not running, the UE may set the HARQprocess ID of CG PUSCH 2 to 1 and perform retransmission of the firstMAC PDU on CG PUSCH 2. The UE may (re)start cg-RetransmissionTimerassociated with HARQ process ID of 1 upon retransmission of the firstMAC PDU on CG PUSCH 2 (e.g., at the beginning of the transmission on CGPUSCH 2). Here, the NDI of CG PUSCH 2 may be set to 1 because it is nottoggled when compared with the previous UL grant (e.g., CG PUSCH 1) withthe same HARQ process (e.g., HARQ process ID of 1). If CG PUSCH 2 isconsidered as a deprioritized UL resource (while the transmission on CGPUSCH 2 is ongoing), the configuredGrantTimer and cg-RetransmissionTimerof HARQ process 1 may both be stopped. As a result, when another CGresource becomes available after CG PUSCH 2, e.g., CG PUSCH 3, the UEmay again set CG PUSCH 3 to HARQ process ID of 1 in order toautonomously transmit the first MAC PDU. The UE may consider the NDI ofCG PUSCH 3 to have been toggled when compared with the previous UL grant(e.g., CG PUSCH 2) with the same HARQ process (e.g., HARQ process ID of1). Consequently, even if the network has already (partially) receivedthe first MAC PDU from CG PUSCH 1, it may not realize that the MAC PDUreceived in CG PUSCH 3 is also the first MAC PDU, possibly due to atoggled NDI in CG PUSCH 3. This eliminates the opportunity to performsoft combining.

CG PUSCH 1, CG PUSCH 2, and/or CG PUSCH 3 may also correspond todifferent CG configurations, e.g., retransmission/autonomoustransmission may be performed on a CG PUSCH from another CGconfiguration. The UE may indicate the NDI value, RV value, and HARQprocess ID value of a CG PUSCH (e.g., CG PUSCH1, CG PUSCH2, and/or CGPUSCH3) that corresponds to a CG configuration configured withcg-RetransmissionTimer. The NDI value, RV value, and HARQ process IDvalue may be indicated via CG-UCI that multiplexes with the CG PUSCH.

In some implementations, if a CG configuration of a UE is configuredwith autonomousTx and configuredGrantTimer, and a CG PUSCH from the CGconfiguration is considered as a deprioritized CG PUSCH, the UE maydetermine whether to stop a configuredGrantTimer for the correspondingHARQ process of the deprioritized CG PUSCH based on specific conditions.When at least one of the following Condition 2-1 to Condition 2-4 issatisfied, the UE may consider the HARQ process of the CG PUSCH aspending and/or may not stop the configuredGrantTimer if it is running.

Condition 2-1: cg-RetransmissionTimer is configured in the CGconfiguration.

In some implementations, when a UE is configured with a CG configurationthat includes autonomousTx and configuredGrantTimer, the UE may, upon aCG PUSCH corresponding to the CG configuration being deprioritized, stopthe configuredGrantTimer for the HARQ process of the CG PUSCH ifcg-RetransmissionTimer is not configured in the CG configuration. Incontrast, the UE may consider the HARQ process of the CG PUSCH aspending and/or may not stop the configuredGrantTimer for the HARQprocess of the CG PUSCH if cg-RetransmissionTimer is configured in theCG configuration. FIG. 6 is a schematic diagram illustrating newconditions to stop the CG timer (e.g., configuredGrantTimer), accordingto an example implementation of the present disclosure. Please note thatin FIG. 6, configuredGrantTimer and cg-RetransmissionTimer are denotedas CG timer and CGRT timer, respectively. In FIG. 6, a UE is configuredwith a CG configuration (e.g., CG configuration 1). At least one ofautonomousTx, configuredGrantTimer, and cg-RetransmissionTimer may beconfigured in the CG configuration (e.g., CG configuration 1). Moreover,CG PUSCH 1 (represented by 610 in FIG. 6), CG PUSCH 2 (represented by620 in FIG. 6), and CG PUSCH 3 (represented by 630 in FIG. 6) maycorrespond to the CG configuration (e.g., CG configuration 1). If the UEsuccessfully transmits a first MAC PDU on CG PUSCH 1 that corresponds aHARQ process ID of 1 and an NDI value of 1, the UE may (re)startconfiguredGrantTimer associated with HARQ process of 1 and (re)startcg-RetransmissionTimer associated with HARQ process ID of 1 (e.g., atthe beginning of the transmission on CG PUSCH 1). Subsequently,cg-RetransmissionTimer may be expired/stopped before CG PUSCH 2 becomesavailable. Since configuredGrantTimer of HARQ process ID 1 is runningand cg-RetransmissionTimer is not running, the UE may set the HARQprocess ID of CG PUSCH 2 to 1 and perform retransmission of the firstMAC PDU on CG PUSCH 2. The UE may (re)start cg-RetransmissionTimerassociated with HARQ process ID of 1 upon retransmission of the firstMAC PDU on CG PUSCH 2 (e.g., at the beginning of the transmission on CGPUSCH 2). Here, the NDI of CG PUSCH 2 may be set to 1 because it is nottoggled when compared with the previous UL grant (e.g., CG PUSCH 1) withthe same HARQ process (e.g., HARQ process ID of 1). If CG PUSCH 2 isconsidered as a deprioritized UL resource (while the transmission on CGPUSCH 2 is ongoing), the cg-RetransmissionTimer of HARQ process 1 may bestopped. However, the configuredGrantTimer of HARQ process 1 may not bestopped. This behavior is different from the behavior in FIG. 5 (e.g.,the UE stops both configuredGrantTimer and cg-RetransmissionTimer forthe HARQ process of CG PUSCH 2 in FIG. 5 when the UE determines that CGPUSCH 2 in FIG. 5 is deprioritized).

Condition 2-2: cg-RetransmissionTimer for the HARQ process is runningwhen the CG PUSCH is deprioritized.

Condition 2-3: The MAC PDU obtained/generated for transmission on the CGPUSCH has been transmitted before.

In some implementations, when a UE is configured with a CG configurationthat includes autonomousTx and configuredGrantTimer, the UE may, upon afirst CG PUSCH corresponding to the CG configuration beingdeprioritized, stop the configuredGrantTimer for the HARQ process of thefirst CG PUSCH if a MAC PDU obtained/generated for transmission on thefirst CG PUSCH has not been transmitted on another CG PUSCH. Incontrast, the UE may consider the HARQ process of the CG PUSCH aspending and/or may not stop the configuredGrantTimer for the HARQprocess if the MAC PDU obtained/generated for transmission on the firstCG PUSCH has been transmitted on another CG PUSCH. The other CG PUSCHmay occur earlier than the first CG PUSCH. The other CG PUSCH may havethe same HARQ process ID as the first CG PUSCH.

Condition 2-4: The CG PUSCH is a repetition within a transmission bundleand/or the CG PUSCH is for retransmission.

The first CG PUSCH may be considered for repetition within atransmission bundle and/or for retransmission if the NDI of the first CGPUSCH is not toggled when compared with the NDI from a previouslytransmitted CG PUSCH that has the same HARQ process ID as the first CGPUSCH.

In some implementations, when a UE is configured with a CG configurationthat includes autonomousTx and configuredGrantTimer, the UE may, upon afirst CG PUSCH corresponding to the CG configuration beingdeprioritized, stop the configuredGrantTimer for the HARQ process if thefirst CG PUSCH is for new transmission. In contrast, the UE may considerthe HARQ process of the CG PUSCH as pending and/or may not stop theconfiguredGrantTimer for the HARQ process if the first CG PUSCH iswithin a transmission bundle and/or the first CG PUSCH is forretransmission.

In some implementations, if a CG configuration of a UE is configuredwith at least one of lch-BasedPrioritization, cg-RetransmissionTimer,autonomousTx, and configuredGrantTimer, and a first CG PUSCHcorresponding to the CG configuration becomes available, the UE maydetermine whether to toggle the NDI value for the HARQ process of thefirst CG PUSCH based on certain conditions. The UE may consider the NDIvalue for the HARQ process of the CG PUSCH not to have been toggled ifthe following Condition 3-1 is satisfied.

Condition 3-1: The first CG PUSCH may be used to transmit a MAC PDU froma second CG PUSCH, which was considered as a deprioritized CG PUSCH.

The second CG PUSCH may occur earlier than the first CG PUSCH. Thesecond CG PUSCH may have the same HARQ process ID as the first CG PUSCH.The second CG PUSCH may be considered as a deprioritized CG PUSCH as aresult of intra-UE prioritization. The second CG PUSCH may correspond tothe same or different CG configuration as the first CG PUSCH. The MACPDU may have been generated/obtained for the second CG PUSCH but was notsuccessfully transmitted on the second CG PUSCH. However, the MAC PDUmay have been transmitted on another CG PUSCH that occurs before thesecond CG PUSCH. The second CG PUSCH may be used for repetition within atransmission bundle and/or used for retransmission. The second CG PUSCHmay be considered for repetition within a transmission bundle and/or forretransmission if the NDI of the first CG PUSCH is not toggled whencompared with the NDI from a previously transmitted CG PUSCH that hasthe same HARQ process ID as the first CG PUSCH.

In some implementations, when a UE is configured with a CG configurationthat includes autonomousTx and configuredGrantTimer, the UE may, upon afirst CG PUSCH corresponding to the CG configuration becomes available,consider the NDI value for the HARQ process of the CG PUSCH not to havebeen toggled if the first CG PUSCH may be used to transmit a MAC PDUfrom a deprioritized CG PUSCH, namely the second CG PUSCH. Moreover, theMAC PDU may have been transmitted on another CG PUSCH that occurs beforethe second CG PUSCH.

The configuredGrantTimer and/or cg-RetransmissionTimer for the HARQprocess of the first CG PUSCH may not be running when the first CG PUSCHbecomes available. The HARQ process of the first CG PUSCH may not beconsidered as pending when the first CG PUSCH becomes available. The UEmay transmit CG-UCI to indicate the HARQ process ID of the first CGPUSCH. Moreover, the NDI value included in the CG-UCI may not betoggled.

Consider a case where a first CG PUSCH corresponding to a CGconfiguration becomes available, and the first CG PUSCH corresponds to afirst HARQ process ID. If LBT failure is detected for the first CGPUSCH, the first HARQ process ID may be considered as pending due to thedetection LBT failure indication before transmission on the first CGPUSCH. A first MAC PDU that has been generated and intended fortransmission on the first CG PUSCH may be stored in the HARQ bufferassociated with the first HARQ process ID. As a result, thecg-RetransmissionTimer and the configuredGrantTimer of the first HARQprocess ID may not be (re)started because transmission of the first MACPDU is not performed by the UE on the first CG PUSCH. Subsequently, whena second CG PUSCH becomes available, the UE may set a HARQ process ID ofthe second CG PUSCH to the first HARQ process ID in order to retransmitthe first MAC PDU on the second CG PUSCH. However, it is possible thatthe second CG PUSCH is considered as a deprioritized CG PUSCH as aresult of intra-UE based prioritization (e.g., LCH-based prioritizationor PHY-based prioritization). Consequently, the first HARQ process IDmay be considered as both pending and deprioritized. Finally, when athird CG PUSCH becomes available, whether/how to transmit the MAC PDU onthe third CG PUSCH may need to be defined at the UE. An approach may bekeeping only one type of state variable for the first HARQ process(e.g., either pending/not pending or deprioritized/not deprioritized).Another approach may be treating the first HARQ process as either a HARQprocess ID for retransmission or a HARQ process ID for new transmission.

In some implementations, the first CG PUSCH may occur earlier than thesecond CG PUSCH, and the second CG PUSCH may occur earlier than thethird CG PUSCH. In some implementations, the first, the second, and/orthe third CG PUSCH may correspond to the same/different CGconfiguration.

In some implementations, a UE may be configured with a CG configurationthat is configured with cg-RetransmissionTimer. When a first CG PUSCHthat corresponds to the CG configuration becomes available, the (HARQentity of the) UE may determine a first HARQ process (e.g., with a firstHARQ process ID) for the CG PUSCH and obtain/generate a MAC PDU fortransmission on the first CG PUSCH. However, if an LBT failureindication is received from a lower layer (e.g., PHY layer), the UE mayconsider the first HARQ process of the CG PUSCH as pending.Subsequently, the (HARQ entity of the) UE may consider the first HARQprocess as not pending when at least one of the following Conditions 4-1and 4-2 is satisfied. Please note that pending and not pending may beconsidered as an internal state variable of the UE. Such a statevariable may be maintained in the (MAC entity of) the UE.

Condition 4-1: The first HARQ process is considered as beingdeprioritized.

In some implementations, the first HARQ process may be considered asbeing deprioritized if a second CG PUSCH used for transmitting the MACPDU is being deprioritized. The second CG PUSCH may have the same HARQprocess ID as the first CG PUSCH. The second CG PUSCH may occur beforeor after the first CG PUSCH. The second CG PUSCH may correspond to thesame/different CG configuration as the first CG PUSCH.

Condition 4-2: At least one of the IEs from IE Category 1, as describedabove, is configured in (the CG configuration of) the UE.

In some implementations, a UE may be configured with a CG configurationthat is configured with lch-BasedPrioritization and/or autonomousTx.When a first CG PUSCH that corresponds to the CG configuration becomesavailable, the (HARQ entity of the) UE may determine a first HARQprocess (e.g., with a first HARQ process ID) for the CG PUSCH andobtain/generate a MAC PDU for transmission on the first CG PUSCH.However, the first HARQ process may be considered as being deprioritizedif the first CG PUSCH is considered as a deprioritized CG PUSCH as aresult of intra-UE prioritization. Subsequently, the (HARQ entity ofthe) UE may consider the first HARQ process as not being deprioritizedwhen at least one of the following Conditions 5-1 to 5-3 is satisfied.Please note that being deprioritized and not being deprioritized may beconsidered as an internal state variable of the UE. Such a statevariable may be maintained in the (MAC entity of) the UE.

Condition 5-1: The first HARQ process ID is considered as pending.

In some implementations, the first HARQ process may be considered aspending if an LBT failure indication is received when a second CG PUSCHbecomes available for transmitting the MAC PDU. Transmission on thesecond CG PUSCH may not be performed due to the reception of an LBTfailure indication from a lower layer (e.g., PHY layer). The second CGPUSCH may have the same HARQ process ID as the first CG PUSCH. Thesecond CG PUSCH may occur before or after the first CG PUSCH. The secondCG PUSCH may correspond to the same/different CG configuration as thefirst CG PUSCH.

Condition 5-2: At least one of the IEs from IE Category 1, as describedabove, is configured in (the CG configuration of) the UE.

Condition 5-3: The UE receives DFI that corresponds to the first HARQprocess.

In some implementations, the DFI may indicate ACK (or NACK) for thecorresponding HARQ process. In some implementations, a UE may determinea HARQ process of a UL resource as being deprioritized if the ULresource is determined, by the UE, as a deprioritized UL resource.However, the UL resource may be reconsidered, by the UE, as not beingdeprioritized if the UE receives DFI from the network, and the DFIindicates an ACK for the HARQ process. The UL resource may be a CGPUSCH, a PUSCH scheduled by a dynamic UL grant, etc.

In some implementations, when a first CG PUSCH (for new transmission)with a first HARQ process ID becomes available at a UE, the UE may usethe first CG PUSCH to transmit a deprioritized MAC PDU with the firstHARQ process if DFI indicating ACK (or NACK) has not been received forthe first HARQ process ID. In contrast, the UE may not use the first CGPUSCH to transmit a deprioritized MAC PDU associated with the first HARQprocess if DFI indicating ACK (or NACK) has been received for the firstHARQ process ID.

The HARQ process ID of the first CG PUSCH may be determined by aUE-specific implementation when cg-RetransmissionTimer is configured atthe CG configuration that corresponds to the first CG PUSCH. Thedeprioritized MAC PDU may be stored in the HARQ buffer associated withthe first HARQ process ID. The deprioritized MAC PDU may match the size(e.g., TBS) of the first CG PUSCH. The deprioritized MAC PDU may beintended for transmission on a second CG PUSCH that occurs earlier thanthe first CG PUSCH, and the second CG PUSCH may be considered as adeprioritized CG PUSCH as a result of intra-UE prioritization. Moreover,the second PUSCH and the first PUSCH may correspond to the same HARQprocess ID (e.g., first HARQ process ID) with the same/different CGconfiguration.

In some implementations, if a CG PUSCH corresponding to a CGconfiguration becomes available at a UE, a UE may select a HARQ processID for the CG PUSCH. If the UE selects a first HARQ process ID for theCG resource, and the first HARQ process ID is considered as beingdeprioritized and pending, the UE may determine whether to autonomouslytransmit or retransmit a MAC PDU associated with the first HARQ processID. In some implementations, the UE may autonomously transmit the MACPDU if the first HARQ process ID is considered as being deprioritizedafter it is considered as pending. In one case, the UE may retransmitthe MAC PDU if the first HARQ process ID is considered as pending afterit is considered as being deprioritized.

In some implementations, the MAC PDU may be stored in the HARQ bufferassociated with the first HARQ process ID. In some implementations, theCG configuration may be configured with at least one ofconfiguredGrantTimer, cg-RetransmissionTimer, autonomousTx, andlch-BasedPrioritization. If configuredGrantTimer is configured at the CGconfiguration, the configuredGrantTimer for the HARQ process of the CGPUSCH may or may not be running when the CG PUSCH becomes available. Ifcg-RetransmissionTimer is configured at the CG configuration, thecg-RetransmissionTimer for the HARQ process of the CG PUSCH may or maynot be running when the CG PUSCH becomes available.

In some implementations, if the UE determines to autonomously transmitthe MAC PDU, the UE may perform at least one of the following actions(a)-(c).

(a) the UE may apply IIoT-based repetition parameters (e.g.,pusch-RepTypeIndicator-r16 and REPETITION_NUMBER, numberOfRepetitions)corresponding to the CG configuration when transmitting repetition ofthe CG PUSCH within a bundle.

(b) the UE may ignore the NR-U-based repetition parameters (e.g.,cg-nrofPUSCH-InSlot-r16 and cg-nrofSlots-r16) corresponding to the CGconfiguration when transmitting repetition of the CG PUSCH within abundle.

(c) the UE may consider the NDI bit for the first HARQ process ID tohave been toggled (when comparing with the previously receivedscheduling with the same HARQ process ID). The UE may transmit CG-UCIthat indicates the HARQ process ID of the CG PUSCH, and the NDI in theCG-UCI is toggled for the HARQ process ID.

In some implementations, if the UE determines to retransmit the MAC PDU,the UE may perform at least one of the following actions (a)-(c). The UEmay determine to retransmit the MAC PDU on a CG PUSCH corresponding tothe CG configuration if the UE is configured with cg-RetransmissionTimer on the CG configuration.

(a) the UE may apply NR-U-based repetition parameters (e.g.,cg-nrofPUSCH-InSlot-r16 and cg-nrofSlots-r16) corresponding to the CGconfiguration when transmitting repetition of the CG PUSCH within abundle.

(b) the UE may ignore the IIoT-based repetition parameters (e.g.,pusch-RepTypeIndicator-r16 and REPETITION_NUMBER, numberOfRepetitions)corresponding to the CG configuration when transmitting repetition ofthe CG PUSCH within a bundle. That is to say, the UE may not be expectedto be configured, from the network, with the IIoT-based repetitionparameters (e.g., pusch-RepTypeIndicator-r16 and REPETITION_NUMBER,numberOfRepetitions) corresponding to the CG configuration when the UEis allowed to retransmit the MAC PDU on the CG configuration due tocg-RetransmissionTimer being configured. In other words, the network maynot configure IIoT-based repetition parameters (e.g.,pusch-RepTypeIndicator-r16 and REPETITION NUMBER, numberOfRepetitions)and cg-RetransmissionTimer to a UE simultaneously (in the same CGconfiguration).

(c) the UE may consider the NDI bit for the first HARQ process ID not tohave been toggled. The UE may transmit CG-UCI that indicates the HARQprocess ID of the CG PUSCH, and the NDI in the CG-UCI is not toggled forthe HARQ process ID.

FIG. 7 is a flowchart illustrating a method 700 for a UE for HARQ IDselection according to an example implementation of the presentdisclosure. Although actions 702, 704, 706, and 708 are illustrated asseparate actions represented as independent blocks in FIG. 7, theseseparately illustrated actions should not be construed as necessarilyorder-dependent. The order in which the actions are performed in FIG. 7is not intended to be construed as a limitation, and any number of thedisclosed blocks may be combined in any order to implement the method,or an alternate method. Moreover, each of actions 702, 704, 706, and 708may be performed independently of other actions and can be omitted insome implementations of the present disclosure.

In action 702, the UE may receive a configuration message to configure aConfigured Grant (CG) configuration and a set of HARQ process IDs thatis available for the CG configuration. The set of HARQ process IDs mayinclude a first HARQ process ID for retransmission and a second HARQprocess ID for initial transmission.

In action 704, the UE may determine that a CG PUSCH corresponding to theCG configuration becomes available for transmission.

In action 706, the UE may select, based on a first HARQ process IDselection procedure, the first HARQ process ID or the second HARQprocess ID from the set of HARQ process IDs for the CG PUSCH. The firstHARQ process ID selection procedure may include: determining a priorityof first data multiplexed in the first MAC PDU as a first priority ofthe first HARQ process ID; determining a priority of second data to bemultiplexed in the second MAC PDU as a second priority of the secondHARQ process ID; selecting, based on the first priority and the secondpriority, the first HARQ process ID or the second HARQ process ID fromthe set of HARQ process IDs for the CG PUSCH; and prioritizing the firstHARQ process ID over the second HARQ process ID in a case that the firstpriority is equal to the second priority.

In some implementations, the first data may be from a first set ofLogical Channels (LCHs), the second data may be from a second set ofLCHs, the priority of the first data may be determined based on an LCHwith a highest LCH priority among the first set of LCHs, and thepriority of the second data may be determined based on an LCH with ahighest LCH priority among the second set of LCHs.

In some implementations, the first HARQ process ID selection proceduremay further include: selecting the first HARQ process ID from the set ofHARQ process IDs for the CG PUSCH in a case that the first priority ishigher than the second priority; and selecting the second HARQ processID from the set of HARQ process IDs for the CG PUSCH in a case that thesecond priority is higher than the first priority.

In some implementations, the UE may select, based on the first HARQprocess ID selection procedure, the first HARQ process ID or the secondHARQ process ID from the set of HARQ process IDs for the CG PUSCH in acase that a Logical Channel (LCH)-based prioritization indication, a CGretransmission timer, and an Information Element (IE) for enabling thefirst HARQ process ID selection procedure are configured. In someimplementations, the IE may be configured for the CG configuration orfor a MAC entity of the UE. In some implementations, the UE may select,based on a second HARQ process ID selection procedure, the first HARQprocess ID or the second HARQ process ID from the set of HARQ processIDs for the CG PUSCH in a case that at least one of the LCH-basedprioritization indication, the CG retransmission timer, and the IE isnot configured. The second HARQ process ID selection procedure mayinclude: prioritizing the first HARQ process ID over the second HARQprocess ID. In some implementations, the UE prioritizes the first HARQprocess ID over the second HARQ process ID may mean that the UE selectsthe first HARQ process ID for the CG PUSCH rather than the second HARQprocess ID.

In action 708, the UE may transmit, based on the selected first orsecond HARQ process ID, a first Medium Access Control (MAC) ProtocolData Unit (PDU) for retransmission or a second MAC PDU for initialtransmission on the CG PUSCH.

By enabling the first HARQ process ID selection procedure in a CGconfiguration, the UE is allowed to select a HARQ process ID of a CGPUSCH corresponding to the CG configuration based on the priority of theHARQ process ID.

In some implementations, based on the first HARQ process ID selectionprocedure, the UE may select a HARQ process ID with the highest priorityamong the one or more HARQ process IDs available for the CGconfiguration. In some implementations, the HARQ process ID may be aHARQ process ID for retransmission if a MAC PDU corresponding to theHARQ process ID was not successfully transmitted on a CG PUSCH on the CGconfiguration, and the MAC PDU is stored in a HARQ buffer correspondingto the HARQ process ID. In some implementations, the HARQ process ID maybe a HARQ process ID for new transmission if the HARQ process ID has notbeen occupied. Based on the first HARQ process ID selection procedure,when a HARQ process ID is for retransmission, the priority of the HARQprocess ID may be determined by the highest priority among thepriorities of the LCHs that are multiplexed in a MAC PDU which was notsuccessfully transmitted (and is still stored in the HARQ buffercorresponding to the HARQ process ID). On the other hand, when a HARQprocess ID is for new transmission, the priority of the HARQ process IDmay be determined by the highest priority among the priorities of theLCHs with data available that can be used for generating/multiplexing aMAC PDU for new transmission. In this sense, with the first HARQ processID selection procedure being enabled, the UE may select a HARQ processID for either new transmission or retransmission of a MAC PDU thatincludes the most important data (e.g., data from an LCH with thehighest priority).

In some implementations, when the first HARQ process ID selectionprocedure is enabled in a CG configuration, the UE may, upon determininga group of more than one HARQ process ID with equally highest priorityamong the one or more HARQ process IDs available for the CGconfiguration, prioritize the HARQ process ID for retransmission overthe HARQ process ID for new transmission from the group. In other words,when the group of more than one HARQ process ID with equally highestpriority consists of a HARQ process ID for new transmission and a HARQprocess ID for retransmission, the UE may select the HARQ process ID forretransmission for a CG PUSCH. The reason is that the HARQ process IDfor retransmission corresponds to a MAC PDU which has not beensuccessfully transmitted before. In order to ensure the latencyrequirement of the data in the MAC PDU is met, the UE may prioritize theHARQ process ID for retransmission in order to perform retransmission ofthe MAC PDU first.

FIG. 8 is a block diagram illustrating a node 800 for wirelesscommunication according to an example implementation of the presentdisclosure. As illustrated in FIG. 8, a node 800 may include atransceiver 820, a processor 828, a memory 834, one or more presentationcomponents 838, and at least one antenna 836. The node 800 may alsoinclude a radio frequency (RF) spectrum band module, a BS communicationsmodule, a network communications module, and a system communicationsmanagement module, Input/Output (I/O) ports, I/O components, and a powersupply (not illustrated in FIG. 8).

Each of the components may directly or indirectly communicate with eachother over one or more buses 840. The node 800 may be a UE or a BS thatperforms various functions disclosed with reference to FIG. 7.

The transceiver 820 has a transmitter 822 (e.g.,transmitting/transmission circuitry) and a receiver 824 (e.g.,receiving/reception circuitry) and may be configured to transmit and/orreceive time and/or frequency resource partitioning information. Thetransceiver 820 may be configured to transmit in different types ofsubframes and slots including but not limited to usable, non-usable, andflexibly usable subframes and slot formats. The transceiver 820 may beconfigured to receive data and control channels.

The node 800 may include a variety of computer-readable media.Computer-readable media may be any available media that may be accessedby the node 800 and include volatile (and/or non-volatile) media andremovable (and/or non-removable) media.

The computer-readable media may include computer-storage media andcommunication media. Computer-storage media may include both volatile(and/or non-volatile media), and removable (and/or non-removable) mediaimplemented in any method or technology for storage of information suchas computer-readable instructions, data structures, program modules ordata.

Computer-storage media may include RAM, ROM, EPROM, EEPROM, flash memory(or other memory technology), CD-ROM, Digital Versatile Disks (DVD) (orother optical disk storage), magnetic cassettes, magnetic tape, magneticdisk storage (or other magnetic storage devices), etc. Computer-storagemedia may not include a propagated data signal. Communication media maytypically embody computer-readable instructions, data structures,program modules or other data in a modulated data signal such as acarrier wave or other transport mechanisms and include any informationdelivery media.

The term “modulated data signal” may mean a signal that has one or moreof its characteristics set or changed in such a manner as to encodeinformation in the signal. Communication media may include wired mediasuch as a wired network or direct-wired connection, and wireless mediasuch as acoustic, RF, infrared, and other wireless media. Combinationsof any of the previously listed components should also be includedwithin the scope of computer-readable media.

The memory 834 may include computer-storage media in the form ofvolatile and/or non-volatile memory. The memory 834 may be removable,non-removable, or a combination thereof. Example memory may includesolid-state memory, hard drives, optical-disc drives, etc. Asillustrated in FIG. 8, the memory 834 may store a computer-readableand/or computer-executable program 832 (e.g., software codes) that areconfigured to, when executed, cause the processor 828 to perform variousfunctions disclosed herein, for example, with reference to FIG. 7.Alternatively, the program 832 may not be directly executable by theprocessor 828 but may be configured to cause the node 800 (e.g., whencompiled and executed) to perform various functions disclosed herein.

The processor 828 (e.g., having processing circuitry) may include anintelligent hardware device (e.g., a Central Processing Unit (CPU), amicrocontroller, an ASIC, etc). The processor 828 may include memory.The processor 828 may process the data 830 and the program 832 receivedfrom the memory 834, and information transmitted and received via thetransceiver 820, the base band communications module, and/or the networkcommunications module. The processor 828 may also process information tosend to the transceiver 820 for transmission via the antenna 836 to thenetwork communications module for transmission to a CN.

One or more presentation components 838 may present data indications toa person or another device. Examples of presentation components 838 mayinclude a display device, a speaker, a printing component, a vibratingcomponent, etc.

In view of the present disclosure, it is obvious that various techniquesmay be used for implementing the disclosed concepts without departingfrom the scope of those concepts. Moreover, while the concepts have beendisclosed with specific reference to certain implementations, a personof ordinary skill in the art may recognize that changes may be made inform and detail without departing from the scope of those concepts. Assuch, the disclosed implementations are to be considered in all respectsas illustrative and not restrictive. It should also be understood thatthe present disclosure is not limited to the particular implementationsdisclosed and many rearrangements, modifications, and substitutions arepossible without departing from the scope of the present disclosure.

What is claimed is:
 1. A method performed by a User Equipment (UE) forHybrid Automatic Repeat Request (HARQ) process Identity (ID) selection,the method comprising: receiving a configuration message to configure aConfigured Grant (CG) configuration and a set of HARQ process IDs thatis available for the CG configuration, the set of HARQ process IDsincluding a first HARQ process ID for retransmission and a second HARQprocess ID for initial transmission; determining that a CG physicaluplink shared channel (PUSCH) corresponding to the CG configurationbecomes available for transmission; selecting, based on a first HARQprocess ID selection procedure, the first HARQ process ID or the secondHARQ process ID from the set of HARQ process IDs for the CG PUSCH; andtransmitting, based on the selected first or second HARQ process ID, afirst Medium Access Control (MAC) Protocol Data Unit (PDU) for theretransmission or a second MAC PDU for the initial transmission on theCG PUSCH, wherein the first HARQ process ID selection procedureincludes: determining a priority of first data multiplexed in the firstMAC PDU as a first priority of the first HARQ process ID; determining apriority of second data to be multiplexed in the second MAC PDU as asecond priority of the second HARQ process ID; selecting, based on thefirst priority and the second priority, the first HARQ process ID or thesecond HARQ process ID from the set of HARQ process IDs for the CGPUSCH; and prioritizing the first HARQ process ID over the second HARQprocess ID in a case that the first priority is equal to the secondpriority.
 2. The method of claim 1, wherein: the first data is from afirst set of Logical Channels (LCHs), the second data is from a secondset of LCHs, the priority of the first data is determined based on anLCH with a highest LCH priority among the first set of LCHs, and thepriority of the second data is determined based on an LCH with a highestLCH priority among the second set of LCHs.
 3. The method of claim 1,wherein the first HARQ process ID selection procedure further includes:selecting the first HARQ process ID for the CG PUSCH in a case that thefirst priority is higher than the second priority; and selecting thesecond HARQ process ID for the CG PUSCH in a case that the secondpriority is higher than the first priority.
 4. The method of claim 1,further comprising: selecting, based on the first HARQ process IDselection procedure, the first HARQ process ID or the second HARQprocess ID from the set of HARQ process IDs for the CG PUSCH in a casethat a Logical Channel (LCH)-based prioritization indication, a CGretransmission timer, and an Information Element (IE) for enabling thefirst HARQ process ID selection procedure are configured.
 5. The methodof claim 4, wherein the IE is configured for the CG configuration or fora MAC entity of the UE.
 6. The method of claim 4, further comprising:selecting, based on a second HARQ process ID selection procedure, thefirst HARQ process ID or the second HARQ process ID from the set of HARQprocess IDs for the CG PUSCH in a case that at least one of theLCH-based prioritization indication, the CG retransmission timer, andthe IE is not configured, wherein the second HARQ process ID selectionprocedure includes: prioritizing the first HARQ process ID over thesecond HARQ process ID.
 7. The method of claim 6, wherein prioritizingthe first HARQ process ID over the second HARQ process ID comprises:selecting the first HARQ process ID for the CG PUSCH.
 8. A UserEquipment (UE) for Hybrid Automatic Repeat Request (HARQ) processIdentity (ID) selection, the UE comprising: one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon; and at least one processor coupled to the one or morenon-transitory computer-readable media, the at least one processor beingconfigured to execute the computer-executable instructions to: receive aconfiguration message to configure a Configured Grant (CG) configurationand a set of HARQ process IDs that is available for the CGconfiguration, the set of HARQ process IDs including a first HARQprocess ID for retransmission and a second HARQ process ID for initialtransmission; determining that a CG physical uplink shared channel(PUSCH) corresponding to the CG configuration becomes available fortransmission; select, based on a first HARQ process ID selectionprocedure, the first HARQ process ID or the second HARQ process ID fromthe set of HARQ process IDs for the CG PUSCH; and transmit, based on theselected first or second HARQ process ID, a first Medium Access Control(MAC) Protocol Data Unit (PDU) for the retransmission or a second MACPDU for the initial transmission on the CG PUSCH, wherein the first HARQprocess ID selection procedure includes: determining a priority of firstdata multiplexed in the first MAC PDU as a first priority of the firstHARQ process ID; determining a priority of second data to be multiplexedin the second MAC PDU as a second priority of the second HARQ processID; selecting, based on the first priority and the second priority, thefirst HARQ process ID or the second HARQ process ID from the set of HARQprocess IDs for the CG PUSCH; and prioritizing the first HARQ process IDover the second HARQ process ID in a case that the first priority isequal to the second priority.
 9. The UE of claim 8, wherein: the firstdata is from a first set of Logical Channels (LCHs), the second data isfrom a second set of LCHs, the priority of the first data is determinedbased on an LCH with a highest LCH priority among the first set of LCHs,and the priority of the second data is determined based on an LCH with ahighest LCH priority among the second set of LCHs.
 10. The UE of claim8, wherein the first HARQ process ID selection procedure furtherincludes: selecting the first HARQ process ID for the CG PUSCH from theset of HARQ process IDs in a case that the first priority is higher thanthe second priority; and selecting the second HARQ process ID for the CGPUSCH in a case that the second priority is higher than the firstpriority
 11. The UE of claim 8, wherein the at least one processor isfurther configured to execute the computer-executable instructions to:select, based on the first HARQ process ID selection procedure, thefirst HARQ process ID or the second HARQ process ID from the set of HARQprocess IDs for the CG PUSCH in a case that a Logical Channel(LCH)-based prioritization indication, a CG retransmission timer, and anInformation Element (IE) for enabling the first HARQ process IDselection procedure are configured.
 12. The UE of claim 11, wherein theIE is configured for the CG configuration or for a MAC entity of the UE.13. The UE of claim 11, wherein the at least one processor is furtherconfigured to execute the computer-executable instructions to: select,based on a second HARQ process ID selection procedure, the first HARQprocess ID or the second HARQ process ID from the set of HARQ processIDs for the CG PUSCH in a case that at least one of the LCH-basedprioritization indication, the CG retransmission timer, and the IE isnot configured, wherein the second HARQ process ID selection procedureincludes: prioritizing the first HARQ process ID over the second HARQprocess ID.
 14. The UE of claim 13, wherein prioritizing the first HARQprocess ID over the second HARQ process ID comprises: selecting thefirst HARQ process ID for the CG PUSCH.